I think I'm having a "stoopid" moment...I can't seem to understand the following instructions from a mitten pattern. This is my first attempt at a mitten. My issue/question is with the highlighted text:

Cuff
Round 1: *K1, p1. Repeat from * to end of the round.
Repeat Round 1 until piece measures 2" or desired length from the cast-on edge. Purl the last stitch of the round.

Thumb Gusset
Round 1: Slip the last purled stitch from the previous round onto the working needle. This will be the first outside gusset stitch. K2, p1. The base of the gusset is formed.

Now, if I just purled the last stitch, isn't it already on the working needle?? Why would I need to slip it on to the working needle? BTW, this pattern is supposedly designed for magic loop (which I'm doing) and not for DPNs or 2 circs. I'd appreciate any and all help and explanations.

they are using "working needle" to mean the one you are working stitches OFF - so slip the last stich of the round (purled) BACK onto the needle, ready to work. Then do the k2, p1

After you've woreed a stitch, it's on the right needle which is the `holding' needle until you get to those stitches again.

When you get around to that purled stitch on the next round, then you slip it.