It looks exactly the same as it did when it left the electret mike - except it's now centered at half the supply rail - so if the electret ouput is swinging +/-10mV, and the supply is 12V, then it's swinging from 6.01V to 5.99V.
I think Audioguru confused you by the term 'modulated', which while technically correct doesn't really help you to understand.
I think Audioguru confused you by the term 'modulated', which while technically correct doesn't really help you to understand.