Why it seems to have an infinite repetiton of el in an el

I wonder why that:

Code:

var button = Ext.create('Ext.Button', {
    id: 'Btn',
    text: 'Button',
    renderTo: 'Panel',
}).show();

console.log(Ext.getCmp('Btn'));

If you open the el of the object in the console, there is an exact copy of the button and in the el of the el there is another copy... and this seems to be infinite.

Why?

Why it seems to have an infinite repetiton of el in an el