If she didn't know beforehand, then Griselda clearly understood what was going on now with Lei Zhen's behavior.
He was not here to converse with her as an equal but to establish a status of who's the one in charge here.
The rejection of the handshake was Lei Zhen saying she was not worthy enough to shake his hand yet. As for the missing tea, he meant that she was not qualified enough to drink anything from their source.
In other words, he was outright saying what qualified her to have the Commanding Officer post and converse with him.
'This person is indeed not easy…' Griselda thought to herself. She was not offended by this treatment because she would have done the same if the situation was reversed.
After all, she was still a stranger who subtly used a threat on Kate to bring herself here.
"Tea or not, we can always drink some of them later." Griselda smiled lightly, cleverly answering Lei Zhen's provocation.
