It doesn't have to mean anything. He knows her well, he's got a decent eye for spatial reasoning, it's not the end of the world if they put it back on the rack. Besides, if he's more familiar than he ought to be he's familiar with a body she can't picture-- the same height, of course, but maybe she's put on weight or lost it. (Put it on is likelier; she knows the kind of shape she's in, and it isn't good.)

She takes advantage of the moment to scoop up a five-pack of underpants and some plain pyjamas-- the latter take longer than she expects, the fashions having tended towards lacy camisoles and printed pants that mean nothing to her. The satin set she's found cost far more than she wants them to and scream little old lady, even to her, but they'll be comfortable, and he did say not to bother about the price. A pack of plain socks; she'd rather do without hose, and somehow the selection here makes her wonder if they've fallen out of fashion. For jeans, she grabs a couple of pairs to try-- the fit is too different to guess with certainty-- and a pair of black slacks, too.

On the bright side, it's empty enough-- and Mulder is tall enough-- that he's not hard to find.

"What have you got? I think the fitting rooms are towards the back." He can wait outside somewhere, surely.