Pick up stitches...???

I’m making a “t shirt” for a pocket poppet… the neck instruction says …pick up 40 stitches around the neck edge… I’ve never seen this before, what does it mean??

I googled it and found a pretty good video, but I’m still a little confused…

Here’s the video from this site:

It helps to mark the beginning, the halfway point and then the 1/4 and 3/4 points around the neck. Then you can keep to ~10sts per segment. You’re just pulling a loop of yarn through a completed stitch and adding the new loop to the righthand needle.