Define Thatswhatshesaid Meaning

At a hardware store. Woman speaking to employee:

She: "The pole I have doesn't fit in the opening tight enough. Do you carry one that's a little fatter that will fit more snugly?"

Employee's thought bubble: "This is a PERFECT thatswhatshesaidism. But I might get fired. I better not. Ah, screw it, I can't help myself."

Employee's response: "That's what SHE said!"

She: "Manager! Get the manager right now! Who do you work under? I need him right now!"

Employee's response: "That's what SHE said!"

A) Dude did you go to the show last night?"
B) "No, I was at work, who played?"
A) "This cool awesome new band from centreville virginia called Thatswhatshesaid!"
B) "OMG i heard they are awesome! I can't believe i missed their show!"

Jim: it’s too big
Michael Scott: thatswhatshesaid