She was telling him “None of your business!” in an intentionally rude way. He walked in, she obviously snapped her computer shut. Then he asked what she was intentionally keeping from him. I think its plausible she was saying “I snapped the computer shut because it is private. Why would you ask after something when I signalled so clearly it was private. Do you really expect me to just tell you the answer immediately after making it clear you are not supposed to know?” This means it could be her doing work of her own that is private (eg. she does digital art in some weird sub-community and doesn’t want the “hey, that image is cool what is it?” discussion.)
I think an important theory is missing here:
She was telling him “None of your business!” in an intentionally rude way. He walked in, she obviously snapped her computer shut. Then he asked what she was intentionally keeping from him. I think its plausible she was saying “I snapped the computer shut because it is private. Why would you ask after something when I signalled so clearly it was private. Do you really expect me to just tell you the answer immediately after making it clear you are not supposed to know?” This means it could be her doing work of her own that is private (eg. she does digital art in some weird sub-community and doesn’t want the “hey, that image is cool what is it?” discussion.)
Another theory is she thought she had been hired for performing another service entirely and this was her way of breaking the ice.