It's a fine line to walk: he has to present himself as similar enough to the Bruce Wayne of his own life that Tim will trust him and cow to his authority, but different enough that Tim will be too unsettled to try too hard to pry into his business. As he isn't privy to anything besides a few disturbing notions and a broad watercolor of that other world, all he can do is allow glimmers of what he knows to be alike shine through, as if incidental, and hope that it's enough.

He's not actually gone for very long - the woman who runs the kitchen downstairs has decided Tom is funny (she, genuinely, is not from Earth), and will make his food for him promptly as long as he chats with her as she works. So he's already halfway through his steak and egg burrito, sitting on a bar stool in the dilapidated near-empty kitchen, by the time Tim gets out of the bathroom. There's a second one still wrapped in yellow butcher paper waiting on the end of the counter, something tenuously between a lure and a peace offering, though it comes with no remark or even notable acknowledgement from Bruce.