It's really weird. Every image shows a device that looks like it is intended to be used with your left hand, except for one tiny image of someone actually using the thing. In that image, they are using it with their right hand, and the device in that image looks like a mirror image of every other image on the page. WTF?
It is for your left hand since most gamers use the WASD keys for movement. Here's a video of a similar design being used to play Quake. https://www.youtube.com/watch?v=xyVSANPnLlg
[EDIT]
The Azeron comes in both right- and left-handed versions so that's why some images show a right hand. The Azeron works similarly to one half of a DataHand keyboard.
Yes - this is the issue for me with the Razer controllers: They are right-handed only. Like the Sherbet, the Azeron is 3D printed, which of course makes it much easier to manufacture left-handed models. The Azeron looks good, but at nearly 200 euros it's pretty pricey.
Mouse is always in the right hand and that's used for aiming (in shooter games at least). Typically left click is fire and right click is aim-down-sights.
[UPDATE] Based on a link in another comment I went to this site:
https://www.azeron.eu/
It's really weird. Every image shows a device that looks like it is intended to be used with your left hand, except for one tiny image of someone actually using the thing. In that image, they are using it with their right hand, and the device in that image looks like a mirror image of every other image on the page. WTF?