[fc417fc802]

I don't think most people view a table for one at a cafe as a social setting with regard to total strangers. It will depend of course and there will be associated social cues; reading anything be it a screen, a book, or something else is a strong cue against unsolicited social interaction in almost any context.

[Acrobatic_Road]

It depends, it depends. You need to look at other signals. Are they extremely absorbed? Is it somewhere extremely quiet (like a library), or somewhere louder (like a coffee shop)?