Here's a way to show a few images in Photoshop without the distraction of palettes and menus.
1. Only have open the images you want to show
2. Hold down the Shift key and click on the third icon (as show below). That will change all the images to full screen mode.
3. Press TAB to hide all the palettes
4. Press Control Tab (on Mac & PC) to switch between open images (use Command/Control + to zoom up if you need to)
To get out of this mode, press Tab to show the palettes and "F" to return to standard screen mode.