I think Trump sent a note to them via the SS agent. It was probably just a nice note of condolences, but Jeb and the other bushes HATE Trump. Jeb’s look was more one of disgust.
None of the Bush’s would have reacted that way to a note of condolence. That would be against a deeply engrained code. They don’t like Trump, but they would gracefully acknowledge an intended courtesy, no matter who it was from.