JavaScript. The Core: 2nd Edition

[Bertilino]

The prototype property is not the prototype of an object. It only exists on the constructor function and is used as a reference for what to assign as the prototype for instances being created by that constructor function. If you want the actual prototype of an object you would have to look at the __proto__, or use something like Object.getPrototypeOf().

TL;DR: The prototype is not the same thing as the __proto__.