By left-clicking on the relevant content, you will open the configuration section. Once you have selected an individual piece of content, you have several different ways to modify the behavior of this content within your Playlist.
Set the duration of the content
You can determine how long the content will be shown, by entering the desired display duration.
Set the sound settings
You can determine which content you would like to be played with or without sound. Just click on the small box to the left of "Play sound" to activate or deactivate sound for the selected content. Confirm your changes by clicking on the "Save Changes" button.
To edit the time control of a piece of content, select the desired Playlist from the menu on the left and then select the content to be edited.
You can find more detailed information on time controls here.