You are not an animal.
Which is to say, it is not the substance of what you eat that matters; you do not convert food to energy, matter, life. You are a spirit in the shape of a person, a pit in the mouth of the world; as you are a sign, a symbol, so too is your food. It is, in a sense, arbitrary. You do not suffer from iron deficiencies.
Nevertheless, you find yourself thinking in animalistic terms. Hunting, preying, stalking, digesting. Snakelike, you stuff yourself powerfully once, then slumber for weeks, months, years, rising only to feed again, to coil slightly against a warmer rock. You tell yourself you are dispassionate, as a snake is dispassionate, meaning perhaps no more than that your face is not built for the convenience of men.
It is easy enough to blend in, there on the upper floors. You know how they speak, dress, act, move. The casual possessiveness you assume is a shadowy reflection of their own, the right to touch and not be touched, to offend and be unoffended, to yell and pound the table and be nevertheless coldly logical. There is nothing you cannot do.
You would think they would be wary, but not so. Apex predators, they are unused to looking for any threat except their own folly. Knock gently on the penthouse door, and be invited in, vipers imagining themselves dragons, ready to warm themselves on your regard.
Then sleep the sleep of the just, for years, decades, or centuries, until need or desire calls you back. No windows are locked above the fifteenth floor.