She only looks decent when someone with a paint brush and some decent clothes sense gets hold of this dame. Otherwise she doesn’t give a rats a** what she looks like. I think it is her way of giving America the third finger salute.
My perspective is that Michelle is resentful towards her go-go never home husband and she doesn’t want to be in the public eye and never waanted to be the First Lady.
Middle Class proffesional and family but her husband has other dreams/goals.
Hence the non compliant attitude to change her comfort zone for the sake of the position of First Lady of the USA. Bitter, Dorthey wants to go back to Kansas er Chicago.