These are the neon lights on the ceiling reflecting on the ground.
But I have to admit I have never been in a real hanger so I have no idea if the floor in a hangar is so polished or more dirty concrete or asphalt-like with no reflections at all.
I don’t think this is anything to be bothered about, just Asobo showing off some fancy graphics.
As far as realism goes, I had a 22 year career in the Royal Air Force and I have been in plenty of hangers on air force bases, navy bases, and civilian airports, around the world, and I can say for sure that I never saw a polished floor. In fact it goes against common sense, not to mention health and safety rules. For example oils spills etc. and shiny floors are a really bad combination. But of course it is a big world and maybe somewhere someone was dumb enough to do it.
I am no more bother by this, than other aspects of MSFS just just seem to be OVERDONE for the sake of showing off.
It’s just a shame that so many feature of MSFS which is meant to be "Today’s best “Flight Simulator” is so flawed with unreal features, but if one stops thinking of it as a “Flight Simulator”, and more of a Money making X-Box game, then somehow, it’s not so bad !!
2022 with be an interesting year when XP12 gets released, and then hopefully MSFS will “step up it’s game” (Excuse the PUN !!! )
Additionally, non-skid properties are an integral part of all flooring systems we offer for airplane hangars, as a slip or fall could be incredibly dangerous in a busy facility full of personnel and aircraft.
And yes, the overhead lights do reflect, just as they do in MSFS !!
But it sure “looks” Slippery,
(Would look great on my garage floor !!)