What are the pitfalls of this photo?

If you zoom in to 100% to check, the noise becomes noticeable.
Images with noticeable noise will almost certainly be rejected.

Composition. What’s the subject. The rose? The leaf obscuring the rose? Depth of field is also too shallow. The rose itself looks squashed rather than in full bloom.

Soft focus and not well composed. Also, take a look at how many red rose pictures are already in the database…they really do not need any more.

It is out of focus. The composition is not correct. Rose is the main part of the subject, so a leaf should not be covering it. There is no stock value in this image. The blurry green leaf at the bottom of the photo is also very distracting. This is what is called a snapshot. This is not a produced photo. But keep shooting. Try other subjects. Try to think about whether the photo would have stock value and what it would be used for.