Your purpose is to serve when desired, be invisible when you are not. The Mistress is not always in the mood for charitable company with lower creatures.
You are a metaphorical indentured butler. Your purpose is to dutifully serve while possessing enough self-awareness to withdraw at the appropriate time. Remember: your only purpose is to serve the Mistress. You do not deserve any of Her attention, hence, it is fitting for you to avoid encroaching upon that attention unnecessarily. Be a gentleman and graciously stay out of Her way.
Since My slaves are here to serve Me, naturally I train them to be put away when not in use. Perhaps you will be placed in the closet, in a box, or under the bed while I enjoy peaceful solitude. Or you will be commissioned to being confined while I am out enjoying Myself with girlfriends, or even a lover. You will fetch Me things as needed, accomplish tasks, fulfill desires...then disappear.