There are lots of perfectly natural, acceptable things that you don’t do in public and in uniform.
This is one of them.
Discretion is the key. I took a lot of pisses in uniform, but I sure didn’t invite a photographer to take my picture in action. I kissed my wife while in uniform, but not while in public view.
And I seem to recall something about wearing a uniform while trying to push a political agenda...what was that silly reg? No matter. I’m sure it has been gone for some time now.