This is the art for when the player in the new game uses their Synergy Coil, an item that uses the energy flowing from Uttermost Island's rifts to use a gimmick. Pokemon that Mega Evolve, Terastallize or Max will glow green, due to the fact that they used Synergy to attain that form. And Z-Moves will glow green too.
do you like it however this energy is highly unstable and you may or may not have to defeat a giant glitch monster in a control room