It would be really cool if there was skin details such as pimples and stretch marks and allergic reactions that show up on a House skin (I. E. rashes or blisters)
Other Zois could react to your Zois appearance (bad Zois would mock your appearance, good Zois would be supportive of your Zois appearance. Their reaction should also be tied to their relationship status with your Zoi)
Also there could be new animations for applying skin treatments or visiting a beauty clinic in order to get a medical treatment.