This option used to set global setting like caption position, preferred image size,image scaling at deck level. If this option is set to off then slide level setting are applied
Use Global Settings :- This option used to set 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 feature images on a slide are scaled.