Composition is a quality issue. In my opinion, the blue background (table?) is pleasing but the vertical element rising from it is ugly and interferes with the main subject. There are other issues, especially with the leaf.
This picture shows the leaf at 100%, which is how Adobe will review it (they may zoom more). You need to do the same, for the entire image.
Did you see the picture? There is no picture in email. If you see no picture, come back to https://community.adobe.com/t5/stock-contributors-discussions/refused-for-quality-issues/td-p/137414...
Click on the picture to open it up. The leaf (because it is the main subject) must be clear, sharp, without colour distortion or other faults.
If you still cannot see what is wrong, you need more training. Consider joining a photo club, but bear in mind that photo club members are not usually trying to make world class commercial shots.
You should inspect your image by zooming in between 100-200% and inspect every part of the image. Doing so reveals that there is significant chroma noise throughout the image, focus is soft and the leaf displays artifacts. I agree with @Test Screen Name that the composition could also have been improved.
Colour clipping (also in the category of the artefacts):
Out of focus, the leaf should be in focus.
You need to level the picture. The pot is the optical orientation:
I also think that the picture is oversaturated.
Any of these reasons will lead to a refusal for quality issues. The moderator didn't spend a second with this asset.
it's solarized and only partially in focus, plus super grainy