I just got the same rejection reply on one of my beautiful lady paintings. What this Adobe rejection notice does not say clearly is, the picture does not have horrible flaws, although the white area is quite loud, This rejection often means that they have many of these sorts of pictures and do not need more at this time. So many photographers shoot and sell these springtime flower shots. You must make your work perfectly focused, exposed and quite unique. I would say: Nice but not needed just now. It might just be clients are doing their own flower shots and not searching Adobe stock for them. JH
Overexposed - the whites burning out, bad cropping, badly composed.
Composition comes under aesthetics, so the composition of your photo is not so good. You should give room around the flower, take it from a different angle - try to make it an interesting shot.
As Oleschwander has said, your picture has other issues. And, unfortunately, it is also not very sharp. Bear in mind, there may be more than one issue when reviewers check the images. In this case, they chose lack of appeal, as I also think it is not a compelling image.
You should really have a read of the guides - the links can be found on the Adobe Stock Contributors forum page at the top.