Although front giants may be trained using straps with an overgrip  to practice certain skills such as inverted giants in eagle grip, the intitial grip required is an undergrip.  Therefore it is important to know how to place the hands on the straps for safe undergrip swings.  In this correct example notice the gymnast is bringing his hands through the strap loops from the front opposite to the way they come in for overgrip.  Observe also that after goin through the loop the hands grab the bar outside the straps instead of in the inside as is the proper case during overgrip strap training.