If you don't mind me asking, how is this reading minds? This is watching for behavioural cues, which lend some evidence of interest/disinterest. Men exhibit similar cues as well - think about the guy sitting at the bar, facing the interior with a grin looking about, versus the guy hunched over with a scowl counting the bubbles in his beer. Unless you're moved by pathos to clink scowling guy's glass, who seems more approachable?

Will admit there are folks who see a single behavioural cue and immediately jump to "They want to jump my bones"/"They wish me and my family were dead", which is dumb. What I'm talking about is more "Oh, looks like they may be open to chat with someone, go say hi", then noting if that impression stays or dissipates on fresh evidence. Again, the biggest problem I've heard of is people, but particularly women approached by men in a social setting, not wanting to tell the approaching party to fuck off (politely or otherwise) because of a perceived or real threat of violence. But this feeling often comes across pretty clearly in body language - if you're a decent person, reading those cues and and exiting gracefully just makes sense.

Discounting non-verbal cues in IRL communication is silly. We give out a lot of information about how we're feeling with our bodies to those paying attention. I'll admit it can sound kinda creepy when writing it all out, but for some folks this is all intuitive. For other folks, thinking about this a bit helps with being more at ease in talking with new people, whether platonically or with an eye to something more.