QQWWU said:
It turns out that uploading links to different sources of the same image is not welcome here, but images from Twitter sources should usually have higher resolution. If an image already has a pixiv-sourced version, should I unupload its twitter-sourced version?
Posting this after this tends to be discouraged. Posting this after this is encouraged. Not everyone follows this, especially users with unrestricted uploads, but anyway... The user I was replying to had posted inferior versions of artworks posted before them (this was posted approximately 2 hours after this got approved).
Idk what you mean by unupload, but if you have a Twitter sourced-version that is less pixelated, has higher res and so on, than a Pixiv-sourced post, then post it and make it the parent, see help:post_relationships for more info. A quick example I can give you with Twitter in mind is Yoshio (55level), this artist uploads superior versions to Twitter, so if people upload from both sources in a short amount of time, chances are that only the best version is going to get approved.