The reason for this is because she can. She feels that her baby is going to look cuter when she places a costume on her child. it can actually work though. Kim is a big influencer with millions of fans all over the world. Something she does is bound to be emulated by a lot of people who look up to her.
This action of dressing up her child in a costume will not go by unnoticed by the community. You will probably find a lot of other mothers who will dress up their children in costumes. They will not necessarily be Dobby costumes but other costumes that will make children look adorable.
She does this because she can dress her baby, the way that she wants to at this point in time. There are a lot of mothers who love dressing their children because it gives them something to do. They know that their babies have the tendency to look cute when dressed in costumes. They would post it on social media and have everyone gush about how adorable the baby looks in different clothes.
She may also be doing this to promote her children’s line that she is sharing managing with Kanye West. If her baby can look good in different clothes, there is no reason why other people’s babies will not look cute especially when dressed in lovely clothes.