How to hide photo bar at bottom of Photo Booth so I can see the extent of the live preview

When I open PhotoBooth, immediately below the live "preview" image there is a strip or bar containing pictures I have already taken. By accident I noticed that this apparently obscured the bottom part of the live image, because when I line up the picture so that the bottom of the image matches the bottom of what I want in the picture, I see stuff below that in an actual capture. How can I hide this bar and see the full extent of the image that will be captured? I don't see any preferences or options to control this. I tried "Tile Window to Left of Screen" and somehow got into full screen which made the window larger so I could see more of the image but didn't make the photo bar go away, and didn't completely expose the entire live preview.