Similar yet slightly different:
I am training my kiddos 9 lb yorkie mix to be a service dog. I have many people look at me questioning, "
HE is a service dog??" Yes, that is what his vest, collar tag, do not pet tag, and id vest badge all say. He wears all this identification when out working and he is trained to public access standards (finishing up advanced training now). Then of course, I hear, "I have never seen a service dog so small!"
I had one person ask me if he is tether training (to restrain kiddo, 13 y/o 76 lbs, from running)....LOL. I would certainly hope/pray a 9 lb dog will never have tether training in their future career

. My kiddo is not a runner, or I would never hook her to a 9 lb dog. Most people cannot tell he has a back up hook actually to her (it is discrete) to back up in case she drops the leash.
I try to view these as teaching opportunities (when I have the patience), rather than letting the questions bother me. But ya know, I have a special needs kiddo, so not much I hear surprises me anymore and even less upsets me. Still, I figure less ignorance in the world is better!