After I read your comment where you said you challenged yourself to draw as fast as you could and not worry about the details, I honestly started to fear you a little. No human could draw something like this "fast" so I have to assume that you're actually a super advanced machine created by the government in a secret bunker for the purpose of making all other artists in the world obsolete.

Seriously though, when I look at this I can tell that it doesn't have as much detail as your normal drawings, but that's like saying a tornado isn't as big as a hurricane. It might be true, but it still knocks you on your ass. You have an amazing talent for drawing group photos, because you draw three things better than almost anyone. Expressions, forms, and poses that reflect the spirit of the character.

In these group pics, most people would take the easy route and copy at least one body type or expression. But you make sure that every character has their own body and their own unique persona reflected through their facial expressions. And they're not just different, they each stand out completely from one another. And the same goes for their poses, you really are able to channel the personalities of each character into their stances.

And just to show you what I mean, let me get specific with my praise. The old TV series Batgirl's cheesy smile and exaggerated super heroic pose totally captured the campyness of that series. Cassandra Cain shows off her mysterious nature with those beady eyes you gave her, and the pose shows how she focuses solely on action rather than words. The new Batwoman's pose and confident expression shows a hint of her alter ego as a rich playgirl. And Oracle immobile and working on the laptop shows that she's all business, and the look on her face shows a hint of urgency, as if she's about to shout out orders for the other batgirls to head into battle.
So I hope you had fun on this, and I am truly amazed that even while working fast you still create something this great.