I don't think the exit row briefing is required by FAA rules. Not all airlines even do an exit row briefing.

Some do, and it's always funny to get a "safety nut" FA who takes it very seriously. I just roll with it.

I was on a UA flight where the FA was going into detail about how many fingers to put into the latch to open the window exit, how to brace one's self to pull it open, and so on. Even before boarding, she had put the safety cards on the headrests as a not-so-subtle hint.

UA's usual is to simply request an affirmative from each exit row pax, which is still more than some carriers do, which is give you a once-over to make sure you look within the age/ability requirements.