I think op it was just unusual,
firstly kids don’t usually say mummy and daddy, other mummies unless very young or upper class. But even then the parent doesn’t tend to repeat it and use those terms too.
secondly teenagers come in all different heights, as the teen years go from 13 to 19, a full blown adult.
thirdly teens tend to wear what many adults do, be it jeans, leggings, hoodie, whatever.
Lastly, unless you are a little person, and even then your child would be used to your height, and I guess you’d say that if you were, then being 5ft or whatever is not unusual. The average woman is 5ft2.
so it didn’t really make any sense on any front. I think that’s why everyone reacted.
kids get embarassed by many things. From your hair to your dress sense. But seldom what you posted, why his clumsy at best, and seldom do parents repeat and say mummy and daddy when their kid is this age.