I see 4 supply registers in what looks line a large room. The big register is a return. I suspect you need all 5 for decent air circulation and cooling.

You may want all those ducts, depending on how the room feels at the peak of summer and winter respectively. If you want to move them around the walls, there's likely a local heating & cooling company that can help you with custom ductwork.

Twintech Heating & Cooling

https://twintechheating.ca/

The registers and return will be less noticeable if you paint them the same color as the walls. The furniture will likely block the view of most of them. I would not spend a money moving duct work. The room is large, has an exterior door, several windows, and a vaulted ceiling. You are not going be going to get away with less supplies, and you are fortunate there is a return.

also make sure the register is turned the right way. you shouldnt be able to see in there.