Co-browsing support: initiated by customer or service rep?

We are currently putting together a co-browse feature for customers using web chat on our website, and the software that was purchased allows the customer to initiate a co-browse session (take control of the pointer etc.) and then waits for the service rep to connect.

My question is should the co-browse feature be initiated by the service rep's end? or continue to allow users to activate the feature from the chat UI, screenshot below: