I haven't had comments quite like that yet, but I've seen a lot of comments that say stuff like, "U0001f44dU0001f44d." Google seems to think it's some kind of emoticon, but there's no way I'd ever have enough time to figure out which image is being used each time I see a comment like that. For all I know, they could be posting a bunch of frowny faces. lol! But, like other people have said, I think your comment looks kind of like a kid playing with the keyboard. Or maybe it was a fluffy cat walking across the keyboard. ^_^