When a current flows in a magnetic field, the field exerts forces on that current. So each current-carrying wire in this Snack generates a magnetic field at the position of the other wire and thus exerts a force on the current in the other wire. Two parallel wires will either attract or repel each other, depending on the direction of current flow in each wire. The forces produced on the aluminum foil are small. This is because the electrical current flowing through the foil is small, only a couple of amperes.
Larger currents produce larger forces.
The Exploratorium exhibit, for example, uses wires carrying 400 amperes, which produces forces that are more than 10,000 times stronger than the forces you produce with this Snack. The ampere , the fundamental unit of electrical current, is defined by the force exerted by one wire on another. For comparison, a force of 1 newton is approximately the weight of a quarterpound of hamburger.