bigger version of the same post

i wanted to upload https://twitter.com/_saaanic_/status/1814397297415073881
but the site warned me its a duplicate of https://danbooru.donmai.us/posts/7878985#
but its bigger and seems better. what do i do

Most of the time if you have a bigger/better pic you can upload it and make the smaller/worse pic its child, see help:upload for more.

In your case you should request image replacement at topic #16765 because the source link is the same, forum #164916 has instructions on how to do that.