Nunu appears to "blink" out of nowhere.

I got this happen to me, in the game, Nunu appears at 0:03 at the minimap, in the middle of the river, and then he blinks next to Kai´sa. Is it a bug, or some game mechanic that just went past me (I didn´t play really in a few years)?? She also appears to see him as to appear out of nowhere, she writes few messages to him.