Template:Exists
meta.wikimedia.org/wiki/Template:Exists
This seems to just be a more verbose version of Template:Exist.
Example
{{exist|File:Cornucopia & Guilds Update Pack.jpg|[[File:Cornucopia & Guilds Update Pack.jpg|300px]]}}
{{exist|File:Cornucopia & Guilds Update Pack2.jpg|[[File:Cornucopia & Guilds Update Pack2.jpg|300px]]}}