As a child, there's nothing more fun than wobbling around in your mother's high heels. A recent Parenting article talked about the reasons children start to role play around two-years-old. And it mentioned the developmental changes that occur at that stage — kids notice changes in appearance, understand symbols and that they can pretend to be someone.
The piece also cited benefits of imaginary play. It said:
"Dressing up's also a crucial way for them to try new roles, rehearse real-life situations, and develop empathy—something they'll continue to do through imaginative play in the years to come. "Kids literally get to walk in other people’s shoes," says Linn. (So don’t freak out if your son is sporting a tiara or your little girl a necktie—it's normal for them to be curious about both genders.)"