At White corp. when Steve got into Jeff's office, they discussed few urgent matters, and Jeff rushed to a meeting. Steve didn't have a chance to talk to him about a woman who is impersonating his girlfriend.
Only later in the day did Steve get a chance to talk to Jeff. "Boss, this morning in the break room on fifteenth floor... it seems that there was a woman impersonating Miss Hill."
Jeff was confused. 'Why would anyone impersonate Sarah?' Jeff assumed that it's Sarah, since she is the only Miss Hill in the company. It didn't make any sense, so he wanted Steve to clarify. "Can you explain this some more?"