What does that phrase really mean? According to Grammarist:
The idiom the devil is in the details means that mistakes are usually made in the small details of a project. Usually it is a caution to pay attention to avoid failure.
An older, and slightly more common, phrase God is in the detail means that attention paid to small things has big rewards, or that details are important.
The devil version of the idiom is a variation on the God phrase, though the exact origin of both is uncertain.
In these cases, again from the Chicago Institute of Art, God evidently won out, as did Thursday Doors.
This photo suddenly was coming out squashed-looking in the post, so I’m going to try adding it again in a different spot and see whether or not that helps. Weird!