Source: Episode 8
Scenario: The battle is about to begin with Gaghiel. With Shinji in the cockpit, Asuka hops over to the main ship and grabs a power plug. The angel barreling down at them - Asuka says that all she needs is her prog knife, and with this sequence she unsheathes it.
Note: This same sequence is the one that's used in the opening (when Unit 02 unsheathes its prog knife and you hear the clap sound) but this particular frame is right before the sequence used in the OP