I'm very new here, so I don't have much experience to go on, but I like how my shop looks much better with the clothes being modeled. When I'm buying something, especially hand made clothes, I like to see them on a person to see how they really fall. Sometimes things can be a lot different than stuff you can buy in the store and I like to know that ahead of time.
When I look at other sellers of pillowcase dresses, most are just on hangers, but I have seen some dresses that don't lay well when worn. That is why I put mine on kids and show what it really looks like.