The point of the break period is to give yourself time away from your work so by nature I'm not sure how 'productive' you want it to be because any other productive activity requires focus. If you want to avoid moving pictures during your break, the optimization of the time doesn't have to be productive:

- go for a walk (even if its only within your work area)

- talk if you're around someone who also needs a break)

- organize your time/ideas for your next task

- water your plants (if you have any)

- play with your dog/cat (if you have any)

- stretching or some other short spurt of physical activity

- work on a puzzle

- chess

- drawing

- meditate

- nap