I have another idea op . You mentioned they are both professionals . Do they have a babysitter and work out of the house ? Maybe the babysitter dresses the baby and saves all the new clothing for when the family is home like Shabbos or the babysitter is just used to using the girly stretchies. Maybe the babysitter snaps a pic of the baby to send to the mother at work and that’s all the pics she has. Could be the mother is busy and forgets to tell the babysitter that the boys outfits should be worn. (I’ve seen mismatched kids and babies that were dressed by babysitters or clueless fathers)