Infantry in particular, and military people in general, are taught how to do parade marches - generally in western militaries as a matter of esprit de corps, but in more authoritarian regimes, because the guy in charge likes to see all the little pawns he gets to command because it makes his dick hard.

When watching a formation march, you’ll often hear someone shouting out a “cadence” that is, some sort of rhythm or marching song that makes it much easier for everyone to automatically sync up their march, so everyone’s stepping at the same time. Generally, this isn’t officially organized - an NCO of some variety will often just spontaneously start that up to help the unit out. And if they don’t, there’s generally a reason.

Again, ask anyone who’s served about whether or not that joke of a parade had any unsaid subtext by the people who were marching. I can just about guarantee they’ll confirm what I’m saying here, and that it was a subtle, rule-following, yet pretty massive snub to orangeboi.