Using Source Viewer

Source Viewer allows you to preview assets that you can add to a sequence. You can also add keywords, markers, or mark-in and mark-out points to the asset. These are preserved when the asset is added to the sequence.

From the menu, select Window | Panels | Source Viewer.
In the Navigator panel, select the bin containing the asset to previewed. The asset appears in the Asset List.
Drag the asset to the Source Viewer.
To navigate through the asset or to add or modify keywords, markers, or mark in and mark out points, use the appropriate transport controls or keyboard shortcuts.