Lovely, crisp shot. Re cropping or composing: There's a rule of thumb in composition (art, photography, anything visual) known as the "60-30-10" rule. It applies to darks-lights-midtones, aka the blacks-whites-grays values in an image. One of those values should be about 60% of the image; a second value (doesn't matter which) should be 30%; the remaining value (again, doesn't matter which) should be 10%.
Therefore, I much prefer the first one, because your light flower is 60%, black background is about 30% (that is, it covers about half the space of the white/light value) and the stamens, or midtones, are 10%. The second image seems cropped too closely; the dark is far less than 30%, and the light value overpowers it, imho, seeming crowded. It always amazes me how the best images follow this rule, at least in Western art.
The image with the white background isn't as dramatic, but it follows the rule; here the pink becomes the 60% midtone, and the white/light is 30%.
Re vertical vs horizontal, I prefer the horiz, but it really is a matter of personal taste. I think they both work; both are beautiful shots with rich color and depth.

For me, it's between #1 and #2... leaning mostly to #2.
I like that little bit of extra contrast/ empty space.

I prefer that orientation over the unusual ones facing up
*GASP and-a-wink!* ... perhaps just on THIS particular flower or example.

In THIS lily, there is a petal either missing or moved or separated naturally away so we can see the stamens... and I love to be able to see so deep down in from a side view.

Additionally, even though you may not have done a single thing different with all four except change the orientation; the pollen looks un-naturally overly bright in the ones facing upwards.

I don't know why... and ya probably should take that with a grain of salt because I'm under the influence of a new pain pill kickin' in as we speak! *blush&

They are ALL LOVE-ly!!
I really love the color and You did a FAB job of capturing it :)

And again but, but, but - not all flowers grow the same way and nature also grows very few flowers by themselves on a black ground. But yes - tis in the eye of the beholder. Regardless; I always like seeing what you have been up to.

I like the original too..... the slight reddish brown of the limbs seem to emphasize the ice. But its fun to experiment.. sometimes it works and sometimes it doesn't. BTW I like your pink lily photos...