The yoda shot shows front focusing - the iphone is in focus at the front. However - that is only what the picture shows. When I did focus testing on my lenses, it took a lot of practice to get the setup correct. I kept up ending up with incorrect focus values that didn't help.
My suggestion is for you to do a test using this method:
Set the camera on a tripod - level with the flat surface you will put your objects on. You want a target to shoot - preferably a large card with this marking on it:
http://safedriving.files.wordpress.com/2010/02/crash-test2.jpg
I drew that on my card with black sharpie. The target MUST be perfectly straight up, and your camera MUST be perfectly level with the target. Any angles will cause you to throw the plane of focus off and misinterpret results.
After you set it up, you should take pictures while adjusting the focus values. You have to be careful not to move the camera - and I suggest you have the camera pre-focus to near/infinity before letting it shoot the target each time. I did this by putting my hand in front of the lens so it racked itself to near focus.
After doing a bunch of values, run it into the computer and do comparisons. Lightroom is really helpful here. When lenses are front or backfocusing, you can spot color fringing at the black/white contrast areas. The less the fringing, the closer you are to being in focus. In addition, the color of the fringing can tell you if you are front or back focused.
This was the test I did to get my Sigma 50 F1.4 to work - since F1.4 is a tiny tiny DOF. A huge mistake I kept on making in checking its focus was to shoot things at an angle. When you want to judge if the focus is corret, you HAVE to judge based on shots that are completely level with the target.
If you want - I can do a photo of my setup when I get home. I used a ruler on an angle to help, since that was what all the focus tests show, but it's actually not necessary. You just need a good target, perfectly leveled setup, and a bit of patience.