So weird

So today at the grocery store as I was checking out, the cashier said something really odd that I am still unsure what to think. She first asked me how old my daughter was and I said 4 months. She then goes "no formula today?" I told her no and then a few minutes later said " I breastfeed her" then she goes " Oh " i said "what" she goes "you just seem like a formula type mom"

I honestly had no idea how to respond because both formula and breastfeeding is great so I just said " nope just breastfeeding and formula is pretty expensive so I hope I can breastfeed until she can start having cows milk."

I am not sure what to think about what she said. I think it was super odd and not sure if she was trying to be rude or what because it really is none of her business to begin with. Has anyone else experienced something like that?