Rolldown return confusion

I think rolldown strategy as whole means coupon income and rolldown return (passage of time), and ability to sell shorter maturity bond at higher price (lower YTM). Blue box 3 in reading 13 does something like this.

My english not the greatest. Rolldown strategy is different then rolldown return? Rolldown strategy includes all 3 above if I’m correct and not same as rolldown return. Thank you