How to make etrex 30x show distance to points of interest on a track?

I recently converted a route with waypoints to a track in Basecamp.
When I navigated the track using the eTrex 30x it showed me the distance to each of these waypoints and approximated time to each.

My question - what makes the etrex 30x decide to show distance to a certain point while navigating? Since a track/breadcrumb doesn’t have the concept of waypoints.