As I’m replacing the images, I hit edit, attach my photos, hit preview. Now that the images are showing, my edit/save buttons are out of the screen, but I see the edit/emoji/reply buttons on the top. If i click the edit btn again, I’d expect to go back to edit mode (from preview mode), but instead, my changes I’m previewing are lost, and I can start over.

Originally reported by Daniel.

So the problem is that when an image in the preview is higher than the viewport, we don't see the Discard / Attach / Preview / Save buttons anymore, because they're off-screen. And a user might expect that the Pen (enable/disable edit mode) button is the same as Preview. This seems to be a UX issue, because enabling/disabling edit mode is not the same as enabling/disabling preview.

One work-around for this would be to disable the Edit button when in preview mode to prevent users from losing their data.