In the Hueco Mundo arc, Episode 139, 19th minute, the passage between gates should be closing from behind but the narrowing of the passage wasn't approaching and though Inoue stayed there for a lot of time and chatted with Ulquiorra while he cuts down Inoue's escorts and she waits and heals them. Such a long time taken and no threat of narrowing of gates till then? What happened suddenly? Why?
The passage doesn't close because they had hell butterflies with them. Hell butterflies are used for both communication as well as keeping the gates from collapsing while they are in them.