Frankly I wouldn't speak to someone about it out there unless they signaled to me that wanted to speak about it first - even then maybe I wouldn't be comfortable at the time talking about it myself in public. You might want to, but that doesn't mean that someone else wants to. At least, that's what I've heard from a lot of trans people on these communities online - not the ones that meet up - where at least a certain % of them doesn't want any acknowledgement from anybody, or mentions that just because two people are trans does not make them automatically friends.
So that might be why - he might have been one of them. Does that top really signify being trans? Maybe he just borrowed it or something. Are you sure he was trans? See I'd be in doubt about my assumptions about a stranger because I've been wrong before. Don't think I'd act on it, even if did want to speak to them - if I really did want to I'd say something different in a different setting, i.e. not talk about that first off but mention it later in conversation... I don't think he could have had much meaningful conversation in a store queue, really. You'd have had to be out of that situation to have a relaxing conversation.
I mean, in everyday life, there's an organic process to becoming friendly with someone. If you went up to any cis person and just started talking to them, I bet some of them would be cold and give you the shoulder just the same because they don't know you. Sometimes if someone comes up to me and starts talking (depending on the situation) I can be cold as well because I just don't want a conversation with a stranger. If they started talking to me about my trans status - I won't lie, I might be borderline offended depending on how they went about it. So... it's probably not that weird he didn't want to be friendly, although what he said and its meaning I have no idea. Maybe you misheard it?
