How to shape neck

I’m working on a Debbie Bliss jacket with seed stitch bands and the instructions are a little vague. Here’s what it says:

Shape Neck
Next row K to last 11 sts, leave these sts on a stitch holder
Dec 1 st at neck edge on every row until 20 sts remain
Cont straight until front measures same as back to shoulder, ending at armhole edge

I am at the point where I have the 20 stitches remaining. I don’t understand what she means by saying front measures same as back to shoulder. Any insight?

Keep knitting on the front until it’s the same length as the back piece to where the shoulder is.