I think people have actually talked about that potentially being a trap by Wolf for the Aliens. Or a trap of Wolf's that back fired on him but either way it's speculation. That was one of the earlier photos so now people are feasting there minds elsewhere (newer "info").
Few problems.There's absolutely no sign the Aliens are in any way restricted except their throats.We've seen other Aliens react this way when touched by Wolf.We know the fights start in the sewers and head out - Those Aliens are goners.