Sure, it is a humorous scene, but I still can't think of the entire film as a comedy. Lots of films have some humorous moments, but aren't comedies.
The entire thing is constantly being satirical of a futuristic, heavily bureaucratic world that treats itself as being a lot more efficient than it is actually is (as in, nothing works).
So it's more, there are a few scenes in which there isn't at least something humorous going on, than it being a movie with humorous moments.
It's actually a pretty good pairing with Playtime in that sense - well, okay, maybe more Mon Oncle. Only Brazil is further in the future and the humor (and the nonhumor) has a very dark tone.