Prefixed or suffixed tildes usually represent temporary files or backups. Sometimes they may persist longer than they’re meant to, which usually means your software didn’t finish a save operation or something similar.
If you have the actual PNG and KRA files intact, it should be safe to delete the temporary/backup files. If you want to see their contents to make sure, just remove the tilde and open them.
Source : Link , Question Author : Lauren Keogh , Answer Author : Joseph Massaro