Transcription from the artist’s impromptu remarks about his own work:
They are enemies because they have different armor. Actually, look: that plate metal guy doesn’t have anything on his shield, and that mail armor guy has a lion rampant on his shield. That’s how they’re enemies.
Plate metal knight: “Hey knight, would you like to punch your head?”
(aside: “What if evil babies laughed like, heh heh heh heh heh…”)
Mail armor knight: “Hey, want to take your armor off? I won’t attack you…”
Plate metal knight: “… um… uh…. Hey, want to punch your head?”
Mail armor knight: “No, I don’t want to punch my head. Would you like to punch your head?”
Plate metal knight: “Hey, no.”