Something doesn't add up-circular directions

Look at these directions:
http://www.knitlist.com/98gift/shrugrecipe.htm

It says she uses size 20" addi circulars but also mentions that she is petite. Okay, I am about 5’5" and measuring even my upper arm doesn’t come close to 20"! Is there a trick here, do you think she is using magic loop or something? I was really excited to not have to sew a seam but I think I would rather have the seam than be working with dpn’s on something that long.

“But mohair stretches quite forgivingly.”

Maybe that’s the ticket. Maybe just for security you could do them on 16’s.

I am new to knitting, so forgive me for being dense. I think those directions sound complicated, but I love the shrug! Does anyone have another pattern for the same style shrug? (So I can compare instructions.)

The pattern doesn’t mention magic loop or two circulars or dpns, but I would challenge anyone to show me how to join a mere 32 stitches in the round on a 20-inch circular. I don’t think even a 16-inch would work. Maybe would work on a 12-inch with bulky yarn.
It’s more than the mohair being forgiving. Something has been misprinted or left out. I think maybe she didn’t join in the round until many of the sleeve increases had been done. My smallest Boye interchangeable is 20 inches. With worsted weight yarn, I think I’d need at least 60 or so stitches before I could even think about joining for circular knitting, and that would be a stretch.

I put this: Bell sleeve shrug on 16" size 7 addi turbos and it BARELY joined. I think I cast on 78 sts. I still haven’t quite mastered figuring out weight so I am not sure how thick the yarn I am using is. It isn’t lace or worsted so it is something in between. I think I will frog it and make it flat, the size 7 seems a little too small for the yarn (it doesn’t have a label so I don’t know the recommended needle size) and when it decreases I would have to use dpn’s anyway.

I really like that bell sleeve shrug but I have a question(s) for you - it doesn’t say she used circulars to do it - did she use straight needles or am I missing something in that pattern?

And what does it mean by “starting with the purl side” does that mean you start with a purl row?
Rows 1-5: Work straight stockinette stitch (st st) starting with purl side.

I think it totalyl depends on the yarn…when making hats I can usually go down to 20 stitches or even less before switching from my 16" circ to 2 circs…but the finished product is nowhere near 16 inches in circumference. Does that make any sense?