The slide show opens in your default browser using your default settings, which might include the main menu, toolbars, a status bar, and a task bar. All the bars and menus won't leave much room to view the slides.
To get the full impact of your slide show, use the Full Screen mode to hide menus, toolbars, and status bars.
The width of the slide frame auto adjusts to accommodate the table of contents frame. When the table of contents frame is displayed, text in the slide frame wraps to the next line.
When the table of contents frame is hidden, the slide auto adjusts to use the full screen width.