A compact pickup describes a smaller pickup package; an electric pickup describes a powertrain. They are not mutually exclusive categories. The meaningful differences appear when a particular compact gasoline or hybrid truck is compared with a particular battery-electric truck: size and loading access may differ, while energy storage, charging, and propulsion operate differently.
Start with what the compact package is intended to do for the owner: carry the required people and cargo while fitting daily surroundings. Then ask how each candidate's power source supports that role. This keeps a small-body advantage separate from a fuel-access advantage, and avoids assuming that every electric pickup must be large or that every compact must use gasoline.