Chrome Javascript console: what does it display in terms of objects?

From javascript console in Chrome:

> function Person(name){this.name=name;}
undefined

At this point, Person.prototype should be an empty object according to Javascript specifications. Let appoint him:

> p=Person.prototype
  > Person

Please note that this> Person is clickable, and it expands to:

constructor: function Person(name){this.name=name;}
__proto__: Object

But ... doesn't that mean it's an empty object? What is this additional material? If you make a warning:

alert(p)

You get [Object Object]. Why, when you enter it into the Chrome console, does it go out s> Face that expands? Doesn't that mean it's an empty object?

Thank!