“Tom is on another planet to his girlfriend, to such an extent that she’s having to teach him a whole new slang language, how to text in shorthand and how to be cool. It is hilarious because he has been showing everyone on set what he has learnt.”
http://www.express.co.uk/comment/columnists/adam-helliker/692631/taylor-swift-tom-hiddleston-cool-lessons

I don't knwo what's the reputation of this website, but this is sadder than the dad dancing and probably an embarrassment to watch. But it explains the use of emojis of a sudden.