My interpretation of the time on the watch was simple. If you noticed the time of the post, it was 3:19. Q was saying he was with the President 5 minutes ago.
I see how well your interpretation fits, but it doesn’t work as a Q proof. I don’t Quite follow why that particular observation would be something Q would use a drop for.
Could it be the importance of the other inanimate items in the photo?
A pen and leather portfolio?
It’s no different than his posts of Trump’s pen or his posts from AF1. Just showing the derps that he’s for real and working with Trump.