Well, is it? I'm a fan of well-done cosplay. For that matter, I'm also a fan of crappily-done cosplay. But I'd rather praise the cosplayers who get it right and creatively embody the characters they portray than make fun of those who choose poorly. Let's praise, shall we?
These two look fantastic and obviously I couldn't be more thrilled with this person's decision to go as Black Bat. She looks better than most of the comic book depictions I've seen so far. The Robin's snazzy, too. The photo description lists Damian Wayne among its tags, so I'm going to guess this young woman is portraying that particular version-- but I prefer her in the role to the hateful little comic book character.
My suggestion to DC? Kill off the comic kid right at the start of your relaunch, loosely base the new Robin on this cosplayer, and then do a team-up book featuring her as a neophyte hero being mentored by Cass. Obviously, I'd buy it.