The screenshot is of Workbench 1.3
There are newer versions of Amiga OS but they're not all compatible with original hardware.
The latest version for classic Amigas is 3.9, and the latest version for newer kit is 4.1
Confusingly, different versions are owned by different businesses - sometimes company 'x' owns one version, 'y' the next and then 'x' the one after. This is mostly down the the fairly chaotic management and dispersal of Commodore's IP after bankruptcy.
Biting the hand that feeds IT
