People keep calling this a professional setting. But it's a press expo. "Booth babes" as popularized by seemingly every video game or entertainment expo evolved out of companies hiring attractive women for their expo booth, to flirt with potential customers. This particular convention one year had a company set up a display of a live "schoolgirl slumber party" that devolved into a lesbian makeout session. Flirting is expected. Sex is shoved in your face.

whether that is a good thing or not is beside the point that standards of professional conduct at E3 aren't the same as a staid business professional gathering.