Assuming you are wanting to present a slideshow in the same manner as a Powerpoint presentation, the options available are limited.
You could use Photostory, to play the project timeline, however this method is IMHO, not a good solution, especially if you are needing remote control.
It is unfortunate that the terminology used in Photostory is 'Slideshow', which is usually associated with PowerPoint or Powerpoint alternatives.
The final 'end product' from Photostory is either a video file or a DVD/BluRay disc, see note below, either would use the respective video/disc players Pause feature.
Note: Chapters on a disc only allow you to jump forwards/backwards to the next/previous chapter marker, however the playback does not stop at the end of each chapter, it continues to the end of the movie. This behaviour cannot be changed on Photostory.
Hmmm, I'm a little slow today. Re-reading John EB's post I realize that "remote control" is exactly what I want. Manual pacing as opposed to preprogrammed X second advance.
. . . . "Here's the next slide. Let me go into a little detail about what you're seeing here" [several minutes of conversation]
"Here's the next slide" . . .
This is a classic case for using presentation software such as Powerpoint, or equivalents, and a remote such as the Logitech R400 Wireless Presentation Remote.
It would be possible as I commented above creating a DVD/BD disc with chapters however this introduces a, IMHO 'messy', 2 click operation, ie next chapter followed by pause on the player remote.
It seems that you still don't understand what PhotoStory does. It's a workshop (project) to build a video file, using photos, videos and audio files, all edited as desired, and to which you can add text and effects. Again, the end result is a video that you watch - it runs by itself. It is not a slide projector. You do not run it from PhotoStory, although you could, but that is not the purpose of PhotoStory.
Further to what John EB says, if all you want is to present a photo, talk live, go to the next photo, talk live... then you can simply put your photos in a folder on your hard drive, rename them to get the order that you want, and run Microsoft Photos which comes with Windows. You have forward and backwards buttons or use the arrow keys. Simple.
But, for Photostory, you would build your "slideshow" (project) adding in titles (text), music, audio, your own recorded narration, all edited over time. Export to a video file (or DVD/BD) and play it back wherever, like on a TV, or upload to YouTube or Vimeo for others to watch. No need for you to talk each and every time.