Making a shrug. Pattern asks to chain enough to comfortably fit "on your arms." Unsure of what this means.

So I have a great pattern, but I'm consied as to what it means. We've previously used stitch markers to mark the back and front of armpit to start sleeves. I'm not sure exactly what and what I'm trying to measure with the chains. I've included a partial image of the pattern with the confusing part highlighted. I've also added what the final product looks like as well as where I am in the patter (so far). (Note: I'm doing different colors than the pattern).