When the students gather to hum the song that Hayashida had gone crazy trying to figure out the title of, you can spot Gorilla and Freddie, the two people who actually performed the song in front of Mechazawa! Surely they could've helped out, they were the ones who performed the song! But then you realize that neither Gorilla or Freddie actually speak, which makes a lot of sense of why they couldn't have helped out.
The English title of the humming song is "I'm Human", which explains why Mechazawa likes it so much.
Kamiyama failing to notice Takenouchi, the largest human character in the cast, and ending up sitting on his lap as a result. This scene is like any other Out-of-Character MomentPlayed for Laughs until you notice that Kamiyama has his eyes closed for most of the scene. Kamiyama is the smartest member of the cast, so the scene may be a Deconstructive Parody of Eyes Always Shut, a trope often applied to wise characters.
is "I'm Human", which explains why Mechazawa likes it so much.