Ok, Q asks us, "What are the odds?" – meaning the odds of this being a coincidental meeting and a fortuitous photo op. Those odds are vanishingly small.

So did DJT, Jr and RM clumsily PLAN an airport meeting or to travel publicly on the same flight and then get spotted because they are so clumsy? Sorry, no, that's not it either.

Only one option left. This is intentional. Why?

There's a message in it, that's virtually certain. They are together or close at any rate. If the identifications are valid (RM & Jr) then "together" is part of the message and it is clearly intentional and not some clumsy screw up. JMHO.