Parents, does this sound like a punishment?

My mom think I fibbed to her about cleaning my room ( I did! ) and my mom sentenced me to a week of being grounded. Today, she woke me up and said she had a second punishment: I have to go watch a bratty little seven year old along with my 4 year old brother today in a crowded store of - yup, glass. Now, the Mom's just going to be looking the whole afternoon while I watch the kids in a glass store! Does this sound like an appropriate punishment to you?