TWIST-3 Effects in Deeply Virtual Compton Scattering Made Simple

We show that electromagnetic gauge invariance requires a "spin rotation" of the quarks in the usual twist-2 contribution to the amplitude for Deeply Virtual Compton Scattering. This rotation is equivalent to the inclusion of certain kinematical twist-3 ("Wandzura-Wilczek type") terms, which have been derived previously using other methods. The new representation of the twist-3 terms is very compact and allows for a simple physical interpretation.