what is the "get" button on the apple tv 4? According to Using Netflix on your Apple TV, "in the App Store, search for Netflix to find our app, then choose Get to start installation." 

Where is the "Get" button? There is no option on the App Store screen:



It's not on the remote either: https://support.apple.com/en-us/HT205305

Any ideas?
What you're seeing is the listing of the Netflix app in the App Store.

Click on the Netflix app (press the touch surface till it clicks) you have highlighted in your screen shot. This will take you to the app page for the Netflix app and there will be a get button on that page. Click on "Get".