Tough to know exactly what he was thinking, but there are a couple of possibilities ranging from "hey, a raise button, lets see what it does!" on one end of the scale to something like "I dont fancy folding now or calling and facing a big river bet, so I'll put in this much more to see if he really has it" or something along the lines of what I mentioned in the video. I'm not sure he can exploit for ICM reasons though bc as I said somewhere in one of the later parts, the element of your range that gets screwed over the most if someone can apply ICM pressure is the middle/upper middle, when you have the nuts you dont exactly mind getting 3bet, so you counter ICM pressure with more polarity, and psje's turn raise range should be and likely is pretty polar.