It looks like the hospital is a bit overwhelmed, with docs fighting over one of the only free and staffed ORs. Alex (Justin Chambers) and Cristina (Sandra Oh) are practically at each others' throats, and they're dragging what seems like half the cast into the argument.
Then Jackson shows up and starts issuing orders, much to everyone's surprise and, in some cases, annoyance.
It seems to us that Jackson makes good calls here, though we'll have to see how the relevant medical cases play out. But whether he's right or wrong, it's clear he really is the boss, now. But will the other docs really keep taking his orders? In this scene, he's mostly bossing around his peers. We have a feeling the more senior doctors aren't going to be so keen to do everything he says.