[Pharo-users] difference between double dispatch and the method explains here

Hello, I just learned double dispatch. And now for the Robot challenge of exercism Tim has pointed me to this article(https://blog.metaobject.com/2019/04/accessors-have-message-obsession.html) but I fail to see how the move method looks like in that article. I had a conversation with Tim in the exercism channel and the way he explains it, it looks like double dispatch for me. Am I on the right track or do I oversee something here. Roelof