You are typically added as a watcher when someone submits a request on your behalf. In this case, the notification message helps ensure that you are aware of all requests submitted in your name.

Ariba Buyer emails this notification message to a requester when someone adds a watcher to the approval flow to the request. The message indicates which watcher was added and by whom.

This is a courtesy message to inform you of the request's progress through the approval process; It does not require any action on your part.