Thongs provide less coverage than a panty and sacrifice the back portion of the panty in order to remove any visible lines that are created by the derriere seams of underpants.
Coincidentally, that also meant they were focusing on "...every taut derriere muscle of each female Olympic beach volleyball athlete," according to Theresa Thomas of the The Catholic Exchange.
A long-leg panty girdle provides overall support as it shapes your hips, thighs and derriere.
This suit draws the focus upward, to take emphasis off of your derriere.
If, on the other hand, you're proud of your derriere, then this is the perfect mini shorts cover-up to show it off!