There is something going on I just know it.
So when Rhyperiorx got her volcanic maskeraith to level 100 and got its ultimates and all that I decided to take a screenshot of it and post it on the wiki. Couple days later I decided that maybe I should re upload but this time in higher quality, so I took another screenshot and posted it on the wiki, but when I looked at the history of the uploads the one I just uploaded looks exactly like the one in low quality. I knew this because the eyes look the same, so I went to check the file one more time and paid attention to the name, then typed it in, and re uploaded. Strange thing is now that picture looks low quality, but now the second picture has the correct one. Then I decided to re upload again that same high quality picture. To my amazement the most recent one is low quality and the 2nd and 3rd pictures are now high quality. One more time then im finished. Uploaded it and now the 3rd image is high quality not the 5th.
When you upload a new version of an image, the wiki takes a few days to make the new version live. In fact, there is a big warning about this on the page where you upload a new version:
"There are currently issues with uploading new versions of images already on the wiki. (The issue is being looked into. Please do NOT reupload or revert it several times as it will not help.)"
Is that the cause of what you're observing? My advice is to wait a few days, for everything to get sorted out. And in the future upload only when you're really sure that the image is exactly what you want.