Adjusting your media
Images and videos can be resized by adjusting the media area within each slide:
Open a slide and click Edit in the toolbar to begin editing
Hover your mouse over the edge of the media area until you see the resize cursor
Click and drag to increase the media area size. There is a max and min size depending on your layout choice.
You can also hover over the media object in the column and press Fill to make it automatically adjust to the width of the column.