Board Thread:Support Requests - Getting Technical/@comment-5170103-20150917095424/@comment-1251315-20150917100710

They probably compressed the file down to bring it below the required file size. I dislike the really strict background image file size limits, it reduces creativity and the quality of the background, since it can't have fancy content on it: at most, you can have a small bit of stuff relating to your wiki's topic, but the rest has to be plain colour, which is boring. I hope Wikia can consider increasing the file limits on backgrounds to something like 1MB. :/