Status Updates From Out

Makeup,, both Yayoi and Masako wear makeup (could be a physical presentation of their acceptance and potential enjoyment of the act they commited/ helped commit).
Yayoi tells Masako to keep the lipstick on after she forgets she put it on,, potentially their union and shared bond through the murder (red =blood etc...)

Milk (the cat) represents the murder Yayoi commited (she cares at the beginning and slowly disregards it but it still exists watching her).