How do you share a picture slideshow on YouTube?
Previously, you would use a tool like Windows Movie Maker or Picasa to stitch the image files into a video for uploading to YouTube. That addition step is however not required as you can create a video slideshow from pictures directly inside YouTube. Here’s how:
YouTube Photo Slideshow

Create a Photo Slideshow in YouTube

While you are on the YouTube website, click the Upload button and then choose “Create” under “Photo Slideshow.” Here, switch to the Upload Photos section and drag-drop all the pictures that you would like to be included in your slideshow.
Once the photos are in timeline editor (see screenshot), you can drag them around to rearrange their position in the video. On the next screen, you have an option to change the default duration of individual slides and also the transition effect between pictures.
You can add background music to your slideshow though YouTube does not offer an option to upload your own audio files for the slideshow.
You can set the privacy to Unlisted if you would not like the video to appear in YouTube search. Also, YouTube might include ads in your video if you have attached a background track to your slideshow and the revenue in that case is shared with the music creator.