What more do you think will develop? Which conflicting statement are we supposed to believe? The First Lady's spokesman said it was not directed at anyone in particular and was "just a jacket", but the President said it was directed at the media. Both can not be true.
As you said, it's hard to believe that a fashion model picked that jacket out of the blue and didn't mean anything by it. But it's also hard to believe that if it was directed at the media, the White House and the First Lady wouldn't have their story straight.
When it's proven that one or both lie constantly, and getting a straight answer is near impossible, people are going to wonder why and make assumptions that are not going to be flattering to liars.