It just has a better processor and bigger battery - the screen is worse than the Air 2 though.

"The new iPad's display is a step backward from the Air 2. It's not laminated to the glass touch surface and it lacks antireflective coating, two characteristics that were included in the Air 2 as well as the existing iPad Pro. What this means is you'll see a small but noticeable air gap between the glass and display, something that diminishes the effect of actually touching on-screen elements."

Source: https://www.engadget.com/2017/03/22/apple-n...p-not-powerful/

Screen resolution is not the only thing that affects image quality on screen. It is a fact that less work is put into the screen of this new iPad compared to the iPad Air 2.