Some points.

Any person posting a photo or image that was not produced by them and not disclosing that it is not theirs is an ethical issue no matter what their reason.
Especially if by nature one would assume the image is yours.

By posting an image like what was done in the critique section puts this site at risk for civil litigation. Since the lawsuit would not be deemed frivolous it would cost this site substantially to fight such litigation. Especially if there was damage deemed to be done to the artist reputation. Having an image critiqued and by not disclosing it was a drawing could have easily been deemed detrimental to and a misrepresentation of the artist work.
The more reputable the sight and the more profitable the more they are at risk. Some of my attorney friends would take a case like this on contingency if the forum was big enough.(Had enough income)

The admin here is consistent. He has always removed threads that were posted where the primary thread image was taken from somewhere(not the thread creators). It is irrelevant what the reason.

The admin here is really good. As he has said before. Things usually work themselves out over time. You threaten the admins here and you're gone.
Posting more than a single stolen(lifted or,whatever you want call it) is a risk and threat to the admin. They usually let one go per individual.

There have been three cases at least over the last two years that I am aware of where some one has started a thread and not disclosed it was someone else image. One claimed it was an accident and asked for forgiveness. One was "I never had enough time to explain". It didn't take two days and his mother didn't die(LOL). Both of the prior examples were resolved quickly and everyone moved on. In neither case did the perpetrators create multiple threads trying to justify their position.

Every forum that I participate in has this "stolen photo"rule. If they didn't I would not participate.
Viewbug has this rule.
500px has this rule.

The bottom line is no one is going to throw you in jail. It's civil not criminal.
It s more of a civil risk to the site than the individual.

Using an immoral means to justify some self perceived moral ends is absurd.

It starts getting more questionable if the image was modified beyond recognition. In this case is it really enough of a similarity? Maybe.
Could the artist of your modified image been accused of some sort of misrepresenting the original's artist intent? Probably.

The smart thing is to do the right thing. Why would anyone with credibility and integrity want to call into question their moral compass. (Politicians excluded)

Who was it who said "you can't cheat an honest man"?

"It is a common belief that people get rich by stealing in prison and Harvard Business School"

Bottom line is this.

If you do the art like you described and you keep it in you living room...not much risk.
If you sell it locally not much risk
If you create a site and generate a moderate income from the sale. Yep you got risk.
If you became famous and sold these for a lot of money. Let me know so I can contact my attorney for a deal.

Some points.

Any person posting a photo or image that was not produced by them and not disclosing that it is not theirs is an ethical issue no matter what their reason.
Especially if by nature one would assume the image is yours.

By posting an image like what was done in the critique section puts this site at risk for civil litigation. Since the lawsuit would not be deemed frivolous it would cost this site substantially to fight such litigation. Especially if there was damage deemed to be done to the artist reputation. Having an image critiqued and by not disclosing it was a drawing could have easily been deemed detrimental to and a misrepresentation of the artist work.
The more reputable the sight and the more profitable the more they are at risk. Some of my attorney friends would take a case like this on contingency if the forum was big enough.(Had enough income)

The admin here is consistent. He has always removed threads that were posted where the primary thread image was taken from somewhere(not the thread creators). It is irrelevant what the reason.

The admin here is really good. As he has said before. Things usually work themselves out over time. You threaten the admins here and you're gone.
Posting more than a single stolen(lifted or,whatever you want call it) is a risk and threat to the admin. They usually let one go per individual.

There have been three cases at least over the last two years that I am aware of where some one has started a thread and not disclosed it was someone else image. One claimed it was an accident and asked for forgiveness. One was "I never had enough time to explain". It didn't take two days and his mother didn't die(LOL). Both of the prior examples were resolved quickly and everyone moved on. In neither case did the perpetrators create multiple threads trying to justify their position.

Every forum that I participate in has this "stolen photo"rule. If they didn't I would not participate.
Viewbug has this rule.
500px has this rule.

The bottom line is no one is going to throw you in jail. It's civil not criminal.
It s more of a civil risk to the site than the individual.

Using an immoral means to justify some self perceived moral ends is absurd.

It starts getting more questionable if the image was modified beyond recognition. In this case is it really enough of a similarity? Maybe.
Could the artist of your modified image been accused of some sort of misrepresenting the original's artist intent? Probably.

The smart thing is to do the right thing. Why would anyone with credibility and integrity want to call into question their moral compass. (Politicians excluded)

Who was it who said "you can't cheat an honest man"?

"It is a common belief that people get rich by stealing in prison and Harvard Business School"

Bottom line is this.

If you do the art like you described and you keep it in you living room...not much risk.
If you sell it locally not much risk
If you create a site and generate a moderate income from the sale. Yep you got risk.
If you became famous and sold these for a lot of money. Let me know so I can contact my attorney for a deal.