The challenge is to draw the same scene twice. For the left box, you draw using only your left hand. Similarly, for the right box, you draw using only your right hand.
If you are using a tablet, that is the hand that you are using to hold the stylus. For mouse-users, that is the hand that will use the mouse. If anyone wants to print out the page and draw by hand, that is the hand that will hold the drawing utensiles.
Basically, you switch up what each hand does in the box that is marked as the opposite of your dominant hand.
Don’t forget to write which hand is your main hand.
Have fun.