Can you be more specific on a couple things

Hello Henry. Can you give us a timestamp? To know exactly which part you are referring to. By the way you describe thing, I might guess he is either using L to select the linked mesh or just going into local view with numpad slash ( / )

Hi Jim DDugansz ,

You can watch the video more than once 😉

You can also watch it at a lower speed.

But it's Separate  > Selection:


Separate > By Loose Parts would work as well.

And you might want to re-take the Fundamentals of Mesh Modeling in Blender (not just watch it, but do all the exercises as well).

Yes he selected the eyes, which are separate meshes, by hovering the mouse over them and hitting L to selected linked. Then P to separated by selection.