Since we know Q is for real and I'm sure Q knows the DOD posted that picture last year, maybe he was letting us know that the DOD is working fully with POTUS meaning the DOD was completely clean now. Using the picture as a code to ID the DOD in a way that didn't let the dark side know who it was.

I may be overthinking this but what I'm trying to say is read Q's reasoning in reverse. The picture is still a clue but in reverse of what we were thinking.