I don't think aspac wants to 'open' the image in 'Documents, just see a 'mini-thumbnail' against the file name, so I would be surprised if a default programme setting has caused this. With 'Tiles' selected I see the thumbnail but my default 'open' programme only runs if I click on the image.
Aspac - you did not say if you actually tried different view settings or were just looking for 'settings'?
I was looking for something called Settings