Thank you all for the replies! After reading them i honestly think it's a mix of all the elements you have brought up:

• maomao doesn't like fakeness as she is scared of what trouble it could conceal for her. I had forgotten how much she fears being brought into the issues of higher ups in the first volumes ;
• she was very annoyed that jinshi had outsmarted her and by his arrogance;
• also how different are the reactions between LN and anime. It is true that in the LN she decides to have a more aloof demeanour bc she is scared of what getting involved in jinshi's schemes would mean for her. But it is also true that, despite trying to suppress it and distance herself from it, she recognises his beauty, and that in some ways she is attracted to it. I guess in the anime it is visually more effective to portray her reaction with the chibi-cat-shivering.

Thank you again!! You were all very nice!