My guess is that is an electric chair and the controller for it is under his right hand but he's ambulatory so he needs the cane. Likely it's not comfortable to hold it over his lap or up off the floor. Being disabled leads to using work arounds that don't always make sense to able bodied folks. Holding a cane still might hurt more then keeping it in motion. Holding it over his lap might interfere with his hand. He could have balance issues and the cane helps him keep orientated. He could just be stimming. Does the why really matter?

Alright, I get the question. Assuming he has it to help him get up sometimes, look at where he's at, some kind of art auction or something right? Maybe he's been getting up and down a lot, looking at things closer. So he doesnt want to put it back somewhere everytime so he's just keeping it out next to him. And the most natural motion for a cane is to just pick it up and put it down in front of you. Or maybe he's just being a little silly for the camera lol :P

Alpha male shit you wouldn’t understand

For pimpin'

It's called fashion, honey.

Honestly, if I were this dude I'd be swinging that shit like a cheerleader baton!

It's his badge of office, it symbolizes his rule over Arrakis.

Am I blind? What walking stick!? Where TF is Waldo???

I'm guessing they use the motorized wheelchair for traveling longer distances and the stick for walking into inaccessible areas or when it's more convenient to do something while standing.

As for how they're using it, I'd guess it's just a way to carry it with them in the chair since holding it horizontally on their lap might hit people that don't see it, and it is easier to perform that motion than to hold it steady in some other, more awkward position.

ITT: OP learns that people with disability can do goofy stuff just for fun

He's an art pimp what do you expect.

I think it's for when he has to stand. Looks like an airport maybe?

poking stick

Not everyone who is in a wheelchair is completely unable to use their legs. Many wheelchair users can stand or walk, but not for long periods or long distances or without assistance.

He might be able to stand with assistance and is carrying the cane himself for when he wants to stand.

Pimp Cane.

His peripheral likely doesn't include below him and he probably can't easily lean to see what's nearby. Building off that, if he struggles to lean forward then he probably needs the extended reach the stick gives to help with things like pointing at stuff on a shelf. He also might need it to help transfer from the wheelchair to another nearby chair i.e toilet, but his condition/pride doesn't need another person to help.