Press Cmd-7 to open the Timeline tab.

The Layer list includes one layer with four objects. How can you tell? You can count the blue object regions (clips) in the Timeline, or just look at the lower-left area of the Layer region in the Timeline; Motion always shows you how many objects are within a layer. In this case, Motion displays 4 Objects. If you look below the Layer object in the Layer list, you'll see a text object, two still-image objects, and one video object.
Just like the Layer list on the Layers tab, the Layer list on the Timeline tab includes buttons to enable behaviors and filters, and activation boxes to turn elements on and off.
Let's move the playhead to the beginning of the project and look at the elements in the Layer list a little more closely.