Deep Well Convertible Jet Pump. Where to install ejector?

So I'm a woodworker but also stray into many other areas when I have to. I'm going to be installing a deep well convertible jet pump into my shop which has a 70 foot well. After looking at various diagrams I'm a bit confused on how I should set this up.

In this picture the ejector is installed directly on the pump.


But this diagram shows the ejector down at the bottom of the well with a send and return line.


So which is it? Is there a specific situation for each setup?

70 foot well you will be running a 2 line set up. The manual with the pump will tell you what depth the injector should be at. Most are around 25ft

If you already have this well, how many pipes are coming from the well to the old pump? If one, the ejector goes on the pump and is considered a shallow well. If two, the ejector goes into the well and is probably already there; this is a deep well.

If you have the well but there was never a pump on it and it has no pipes coming from it; measure the depth to water from ground level. If it's less than 25 feet, its a shallow well. If it's more than 25 feet, it's a deep well.