LAST EDITED ON Sep-28-15 AT 05:02 PM (EDT)
 
Pretty much this. Corwin, if I remember correctly, is one of the absolute highest-tier gods, in the same ranks as his mother and the other Norns. So, even sealed, he basically has an aura that appeals to those he was given dominion over. Or that's how I read it.

For examples, look to other interactions between Corwin and other sentient machines - Dorothy, Eve and Wall-E come to mind, off the cuff, and Dorothy of course happened before his apotheosis and subsequent sealing. He's also been shown to be capable of 'speaking' in machine languages, including burst code (though his accent is terrible), so there's a great chance he's communicating with them on more levels than just the one we're shown in the story, possibly without even realizing it himself.