I was told that on of these pictures was rejected because of an "exposure issue." Could I get some feedback on these two photos? What would make it better? Are they overexposed?
These photos are wonderful. If there is a complaint about exposure it should be on the shadows, I think. But i wouldn't reject a photo for that in this case. You can try to enlighten the shadows and see if it works.
Maybe, possibly, could be, might be... if one were to nit-pick... the rose could be said to be a bit overexposed. I don't think the shadows are a problem, but the rose petals are a bit too bright and light, especially on the outer petals, so you could bring down the exposure on the roses.
Bear in mind though, there are a lot of flower pictures in the data base, so the next rejection reason might be lack of esthetic and commercial value.
Are you sure it's worth the effort?
I have adjusted the highlights and the exposure.
Added a vignette.
Removed a light spot in the upper right corner.
Be aware that flower shots like this are a dime a dozen on Adobe Stock. That is to say, there are a LOT of them. Even if you get your exposure exactly right, it's still unlikely to be accepted unless there is something spectacular about your image.
In both photos the centre of the rose is seriously out of focus. Flower shots need to be spot on and have a reasonable DOF so that the closer petals are in focus along with the centre.