It's actually sort of freaking Dean out, too, but hearing this... it's also reassuring, as well. Toby's not looking at the tablet, but Dean is, and then he's speaking again and he can't help it.

"I'm not that great of a brother, Toby, really, man. Couldn't even stop Sam from doing all that demon crap, y'know?" Dean wants to stop, he doesn't want to be telling Toby this, or anybody this. "I mean, you shouldn't-- I'm not someone you should trust like that, I'm gonna let you down, I know I will."

And now Dean's looking away, slumping against a wall and dropping his tablet next to him so that it's facing the sky, still on visual.