I guess a big block of cheese around her arm is helping it heal?
I figure it’s a clever piece of gear designed to allow for differing positions in which to rest her limb.
It looks like swiss cheese, so maybe they use yellow foam and call it a cheese-pillow. Which makes things easier for the patient because asking the nurse to bring her the cheese-pillow is easy to say and unmistakable in its intent.
But what it really is, I don’t know.