Excellent rebuttal.
Comparing these two photos (massively different angles, but focus on the lighting, curtains, even that strange cone-ish mark above the window), confirms Trump was indeed on Marine One and not Air Force one (getting interior shots of AF1 is extremely difficult).
Here's Obama in Marine One:
https://commons.wikimedia.org/wiki/File:Barack_Obama_in_Marine_One.jpg
And Trump (with the same background decals):
https://media.8ch.net/file_store/6ff1ef038d84a165a36a8949c8501542f19d6d59c40db86697021fb337b14fe4.jpg
However, this doesn't refute the entirety of the argument, but it does modify and it actually, bizarrely, strengthens it. As Q knew about the fire truck enough to drop hints, and Marine One is a very small craft, we can be assured it's only either the president or those immediately around him.
Until I can get someone nice enough to provide interior shots of AF1 (or to specifically confirm if 5A is a valid seat and if said seat is on AF1), the seating location is up in the air.
However, Q may be playing a very technical game. Technically speaking, any aircraft carrying the president is 'Airforce One'. If the photos were, say, from not the craft most famously associated with it, but Marine One, Q would be pretty much confirming that he is indeed Trump.
Still, the new information modifies my argument and I'd need to reshuffle it. I'm going to wait until I've gotten additional information to contribute, but excellent spot.