The After Image is a power up from 1941: Counter Attack. It is represented by a ship with shadow copies icon.
The After Image will replace the Side Fighter when equipped and vice versa, thus making it impossible to have both equipped at the same time. When collected, the After Image will create two shadow copies of the player's ship, which will mimic the player's movement and fire along with it, essentially tripling the player's firepower. Unlike the Side Ship, it doesn't protect the player from damage but will remain for the duration of the stage.