Was your magnifier part of the image submitted? If yes, leave it out.
There is some noise in the image, it could get a punch of sharpness. But those are only minor. There is a slight blue cast in the white of the wall. That should get corrected.
The framing is also not the best, but I think it will pass.
BTW: pretty good for a drone photo may not be good enough for stock. The quality of a picture is assessed the same way for a cheap cell phone photo up to the most expensive camera. And picture quality needs to be (near to) perfect.
ABAMBO | Hard- and Software Engineer | Photographer