I wasn't convinced just by the look on her face, but if you look at him, he is grinning at everyone then just before he turns back he turns slightly to Melania and his cheek drops, no more smiling and he says something, then turns back round looking pretty pleased with himself.
Without that, I could have believed Melania just had aching cheeks from all the enforced smiling, but there is something sinister about the sudden drop of his cheek.