Overbetting Pots NLCASH

[Indiana]

This is a technique that I don't really grasp that well but I've been seeing a lot of HU cash players overbet pots with big hands. Can we discuss the reasons for doing this and how this may affect metagame? Here's a hand example from the jsnipes video(at 25:30):

snipes has 9Ts out of position and calls a minraise from the btn. flop is J6Q rainbow and he checks, btn checks. Turn brings down the K for his str8 and he bets 2x the pot roughly. For me, I'd just bet like a little less than pot to get some action. Why overbet?