Your encounter with this person will be brief, but you will definitely run across them. They're outside of the venue, wearing a blazer, and pacing, on an imaginary phone call with a publicist who doesn't know that they exist. In between these fruitless calls, they will appear to be texting, but since they don't actually have a contact at the event, that's not what's happening. Instead, they're on Twitter and Instagram obsessively checking for updates on the event and will likely contribute with something along the lines of: "The door at this party is a ZOO!"
There will be tension between this person and the bouncer after several failed attempts at entry, and at some point, the publicist working the door will begin to completely ignore them. They will you ask you and everyone else who's actually on the list if they can get in as a +1, and if that doesn't work, you can catch them eating a lonely meal at the nearest diner—still checking Twitter and Instagram.