You can adjust the size of the media frame, and scale your images and video clips to adjust how they fit within the frame.
Adjust the scale of your images and video clips within the Media Frame
Click on the item you want to resize. Select Scale from the menu that appears, and use the slider to adjust the size. When you’re ready, click on the image to drag to position it, and you’re all set!
Adjust the size of the Media Frame
To adjust the size of the Media Frame, click on the frame you want to resize. Click on the circles on one of the corners of your Media Frame, and drag it until it's the size that you want.