Why it's on the list: Some lifters speak reverently of the bent-over row as the "fourth powerlift." Whether you agree or not, this is a back-focused movement in which you can go very heavy, and with the reverse grip, the biceps are heavily engaged. It's not really the kind of exercise you'd do on a biceps-only day, so it makes a good bridge between back and biceps.
Row Variations for Biceps Growth:
In your workout: Include it in your back routine, or as a bridge exercise when training back and biceps together. Go fairly heavy and train in the classic muscle-building rep range of 8-12 reps.