The sad thing is that Jack needed to psych himself up for this. He can guess that Reinhardt would make his way to the bar eventually, and a quick peek inside confirms that fact. He withdraws for a short time, but it's only to finally rid himself of his tactical gear, steeling himself for a conversation that he knows is a long time coming.

He owes Reinhardt this much, no matter how difficult it is.

When he slides into the seat opposite Reinhardt, it's without the mask and gun and jacket. He looks uneasy and jumpy, like he doesn't want to be here and is half expecting to be caught off-guard, but it's clear this is his effort to present like an actual person. It's for Reinhardt's benefit, of course, which he hopes comes across when he settles himself at the table.

"What are you drinking?"

He'll have what you're having, bro.