Constantly taking someone elses posts and posting them yourself on the iphone/android app "Whisper", claiming they're yours to get likes and comments when you don't deserve them. Therefore being a Repost Whore.
Dis bitch is being a repost whore because she keeps posting posts on Whisper that she stole from either someone on Tumblr, Facebook, Twitter, Youtube, Flickr, linkedin, Google images, and every other social network or search engine out there.
More commonly heard in Discord and other similar platforms, repost in another server simply means two things:
1. The joke you just said was so funny that it should be in another server since it was funny.
2. Please stop talking in this server because we're busy, just repost in another server.
Usually it falls under the latter #2, as a sarcastic version of #1. Sorry.