Poppy W + E

My question is about Poppie's w. As I know this shield blocks ENEMIE'S dashes. So, when Poppy using E with active W, she stops (another enemy near target) and knocks self. Is it a bug or feature of game mechanic? You can view example in the game - CLG vs TSM (game 2, 17.04) on 18:00 - 18:05 game time.

Thanks in advance.