I suggest the following:
When a wallpaper gets reported, make it so that the uploader sees the reason for the report. Also, make it possible for the uploader to delete his wallpaper even if it was reported (I have no idea why a report prevents a wallpaper from being deleted). I'll give an example why this is useful.
I recently uploaded this wallpaper:
I see it was reported and I have no idea why. But I thought... it's not low quality, so maybe it was reported as a duplicate. Then I searched similar wallpapers and found this:
Now I see it is a duplicate and I want to delete it. But I can't! So the moderators will waste time judging reports that could be solved by the uploader.
There could be other examples as well. Maybe if I see the description of the report I will analyze the wallpaper again and delete it. This could save the moderators a lot of time.