Here we have a view of the interior of the backside of this little device, which includes storage for diapers and other changing supplies, as well as a compartment where a week's worth of nutritious, if bland, vitamin paste. Not glamorous, but it's not like this thing can hold an entire kitchen's worth of food. Space had to be saved for some of the inner gears and mechanisms allowing one specific component to operate effectively.
Yes, here we see the rabbit hole goes even deeper: This thing is essentially a sentient AI, more than capable of feeding, changing, and generally taking care of its prisoner. This is largely thanks to its pair of extending arms, which can easily reach out many feet in any direction, whether to pat its occupant's head, ward off potential dangers, or replenish its own supplies, allowing its prisoner to remain inside it indefinitely.
