Sawtooth Thumbnail in Aperture
In my main Aperture library, I noticed an image the viewer that had jagged, sawtooth edges on it. I hadn't seen it before, and believe it's something new with Aperture 3.4. After a little experimentation, it looks to be a visual cue that the crop applied to the photo has an "extreme" width/height ratio such that the thumbnail cannot display the entirety of the photo. An illustration is in order:
In the example above, I did quite an extreme crop of the photo - well beyond a 2.39:1 panoramic ratio. The yellow lines show what area of the crop is visible in the thumbnail. You can clearly see the far edges are not represented in the thumbnail.
The same holds true for extreme vertical crops as well:
It looks weird at first glance. But now that I understand it, it's a good visual cue that the thumbnail isn't a full representation of the image. This is handy when sharing or exporting images from the browser view - and avoiding being surprised later when the exported image isn't what the thumbnail indicated.