On AI-enabled cameras (Vision Analytics) you can highlight people or vehicles via a "bounding box" when hovering over an event on the timeline.
To enable object highlighting when hovering over an event on an AI-enabled camera:
Select the "gear" icon in the top-right of the video player.
Toggle the Highlight Objects option to ON.
Hover over an event along the timeline or on an event on the left-side of the video player (if available) to highlight the associated people or vehicles in the event:



