You should be able to toggle the thumbnail strip on and off. It’s the icon to the left of the three adjustment buttons. See this image link:
I'm not sure which icon you are referring to. I don't see anything that turns off the thumbnail strip, aside from tapping the image to make all the extra stuff go away. HOWEVER, the image doesn't resize. There is still a blank area at the bottom of the screen even after the thumbnail strip goes away. Try it with a vertical image, and you will see what I mean. THAT is my issue.
Oh, I see which icon you mean. The bottom left one. This is the iPad interface, correct? I don't think the app has been fully rolled out for the iPad yet. Just wait. I'm sure the full screen functionality will be gone once they finish rolling out the updates for the iPad app. If you have an iPhone with the lastest update from December 8th, you can try the app there, and see what I mean.
<q>If I tap to view JUST the image, all the other stuff goes away including the thumbnail bar, but the image does not expand to full screen. There is still an empty space on the bottom of the screen where the thumbnail bar used to be.</q>
Having this issue in Android after tapping the screen to hide the film strip etc., but the film strip comes up as a blank area and thus shrinking the image on the screen.
Outlines the issue as well.