How can a web designer explain this without frightening the client?

The easiest explanation is: your website still matters for humans, but AI systems need a different kind of clarity. A Digital Twin sits beside the website and packages the business so AI assistants can understand services, locations, questions, images and reasons to choose the business.

That keeps the conversation positive. The designer is not attacking the website. They are adding the next layer. For web designers, the value is being able to add an AI-readable layer beside the client website without rebuilding the whole business from scratch. Used well, this becomes a clear business conversation rather than a generic AI sales pitch.