It's not a big deal and it shouldn't turn into one. He was likely asked to send a current picture in uniform for the email mailing and the only one he had was in an original United uniform.

I haven't taken a picture in the new United uniform and don't ask me to put the uniform on special just to take a picture. Not gonna happen. But what about the IAH LEC officer wearing CAL WINGS embroiderer on shirt recently while doing a trip - that is blatant no matter the reason. You think it makes the original United guy feel loved and wanted in IAH? Most guys are thick skinned enough to know the score and let it slid.