約束 can also mean "cliché" or "genre convention", especially when written as お約束. Metaphorically it's an "implied promise to the readers/viewers".
Um...
Sure.Someone told me!
That Laffey is!
Willing to!
Clean my ear for me!Why are you speaking all formal!?Well, sir, with all due respect, even if you put it that way...
Laffey switches to polite speech here.How 'bout this?mold...knead...Here, I'm changing it to an S since I'm a commander.
Commander = /shikikan/Sure enough though, leaving it as a P all the time might be weird.This is, well...
You could say it's a tradition of sorts, or a genre convention...I know it's kind of too late to ask, but... Your head, Commander, why is it shaped that way?FAILUREWhere's your ear!?*crack*