How can I take a screenshot of the app switcher in macOS?
Use the timer option in the new screenshot popup app.

 Cmd ⌘   Shift ⇧   5 
Select Capture Entire Screen on the left &amp; 5 seconds from the Options menu



Click Capture.
During that 5s countdown, hit  Cmd ⌘   Tab ⇥   

The resulting image will contain the switcher [intentionally tiny picture]



Interestingly, whilst composing this answer I discovered you can open the Screenshot app, then take a picture of it using the 'old'  Cmd ⌘   Shift ⇧   3  command ;)