You can change the transition effect of your already created slideshow. Follow these steps to do so:
1. Select the slideshow which you want to modify, and then click ⛭ to open slideshow properties.
You also change the mode of the images by clicking Element settings on the properties toolbar.
2. Select a transition effect for your slideshow from the drop-down. The following transitions are available:
Fade - Image gradually disappears and the next image gradually appears.
Slide from left - The next image slides in from the right.
3. Save your page when you're done!
The editor doesn't show the real effect, so make sure to preview it in the Viewer.