Photoshop Demo Mode?

My use of the word "dinky" in my previous post was inappropriate.

To add a final comment, I believe the low-tech option  -- essentially, using a physical mask rather than an electronic mask == has the potential of being an inexpensive practical solution. It is worth a test by the OP -- even by using an old time slide projector in an office setting.

The solutions offered by davescm​​​ and Trevor.Dennis​​​​, while technically adroit seem to offer -- as a series of stills -- a result not that different from Bridge's Slide Show,  while the dinky card & frog solution would be a live demo, showing the Move tool's dragging of elements, the Brush tool in action as well as the action of Transform tool, for example -- while they are being used. The only limitation I see is that Drop Down menus, if any were used, would appear on the screen and that may be a no-no. At any rate, all you have to say.to me is Shut Up and I will. I don't have a Trump gene.   

Hi

If the projector is set up as a second monitor then

1.With Photoshop and your document open on the first monitor, use Window>Arrange >New Window for xxxx  to create a second window for your open document.

2. Move that second window to the second (projector)  monitor.

Whatever you do in the first document window will be replicated in the second - however you will not see the cursor in that second window just the effect of brush strokes etc. immediately after you have placed each stroke.

Dave

Courtney, I. neglected to mention that you could buy a Florist Frog for about $10 that should serve as an easel for the card. This is one of many appearing at the Amazon site. Sorry for the omission.

There is specialist hardware that works with combining, splitting and merging the output from graphics cards. A main part of the consumer of these units is people who set up large scale or theatrical projection projects - for example projecting onto multiple faces of a building from a single running video.

On a more mundane level you might consider Powerpoint as the engine to show video fragments, stills etc. made in Photoshop. It is good at managing presentations over two screens, one being private to you. Best to use a specialist presentation tool anyway, rather than your design tools.

Consider an opaque rigid card with a smallish rectangular aperture placed perhaps. 6" in front of the projector lens so that it allows only the PS work area to be seen on the screen. The size of the aperture and/or its distance from the projector could be adjusted to accommodate the screen size and distance.