Mom misses the point of me acting out/miming tasks

I'm really annoyed at my Mom telling me to use Sign Language signs for  "burger" and "French fries" when I'm was acting out, or miming doing the tasks of fast-food employees 

Background:

I was thinking about some boring job settings over the last two weeks in relationship to two out of three life sim games in development  and two of those games you can follow your pixel (ie human character) to work.  A couple of jobs I think would be a bore, would be  office worker, and teaching.  You do NOT want to know what some people's ideas are to spice up the game but one word: clichés.  

Story:

When I was out shopping with Dad this morning- while waiting for a store to open- I was thinking of other boring jobs and I thought of Fast-food setting.   So I was trying to mine or "act out" the tasks of a fast food employee 

When it was lunchtime at home  when I was trying to show Mom my "miming" or "acting out" the tasks of a fast-food employee she told me to use the Signs for "burger" and "French fries".   She completely missed the point of what I was trying to do.    So I'm kind of really annoyed by that.