You see, the term comes from older vehicle designs, where the gas pedal was on the left of the pedal assembly and you COULD use your heel with your toe that way. So, the difficulty of performing heel and toe shifting is lessened by getting special performance driving shoes which are designed for heel and toe shifting; hence, heel and toe performance driving shoes.
What you actually do is put the left side of your right shoe on your brake pedal’s right side. To tap the gas pedal, twist the right ankle and tap the gas pedal with the right side of the right driving shoe.
However, Primarily it is the technique that enables you to downshift smoothly without needing to double clutch or drop power to the tires. It also allows you to more quickly put torque and power to the wheels for rapid acceleration while keeping the vehicle level. as a matter of fact, Carroll Shelby has a line of performance driving shoes designs especially for this type of driving.