Overview: This option is used to set global setting like caption position, preferred image size, image scaling at deck level. If this option is set to off then the slide level setting are applied.
Use Global Settings: This option used to set the global setting on or off.
Preferred Image Size: This option used to set image size.
Caption Position: This option used to set caption position top or bottom.
Image Scaling: Changes the way that featured images on a slide are scaled.