reason of rejection

The asset is unsharp and there are many artefacts:

Like here aliasing.

Or a border:

And colour banding:

If you had painted it and then scanned the image, you should have scanned at a higher resolution and higher JPEG quality (best would have been saving as a TIFF file), so that no upscaling would have been necessary. The TIFF file could have been corrected in Photoshop and then saved as a high quality JPEG file to be uploaded to the database.

I like the smooth, deep green texture of the leaves, but the edges of the flower are too soft at 100%, as the others have mentioned. You might try some sharpening filters, although I don't know if the yellow pistil can be saved.

Hello,

When you enlarge this to a 100% you can see compression artefacts. This happens when you upscale.

'Painting' I think, is a mistranslation - did you use a translating programme?

It appears that the depth of field is too shallow, causing too much if the flower to be blurry.

Painting? I see blurred edges around the leaves.