Whilst I haven't set any official rules for the gallery, I think the intial thing to do would be to ask the uploader. However:
1. If the uploader is the original artist, then copyright, like any of the stories on Tome, remains their property. Seek their permission before any reproduction.
If the uploaded article wasn't created/isn't owned by the artist, then it depends:
2. If it was just 'lifted', then I'd say you have as much right to use it as the uploader.
3. If it was uploaded with permission from the origial artist, then see 1, and/or get permission from the original artist.
