This shot is in perfect focus, to my eyes.... let me explain...
The wall is demonstrating critical sharpness just behind and to the right of your subject. In fact, the wall is sharp through most of the frame, except the far left and right edges. I think that the AF caught on the wall, rather than your subject. This isn't front focus or back focus.
Most of the time, walls are 'flat' and don't trick the AF. However, the camera isn't doing face recognition or psychically predicting what you want to focus on. It's just saying, "FOCUSED!" on the first thing that it finds to be 'in-focus' across it's 5 or 11 AF points. In this case, it detected that the wall was in-focus and allowed the shutter to release. The highly reflective, shiny wall probably made this even more likely to happen in this case, since the brightest light hitting the AF sensor was coming from the wall, not your subject, making it the first thing to trigger the 'in-focus' designation from the sensor.
I personally can't shoot with 'auto-AF point'. I shoot my K-5 in SEL mode where you pick the AF point to use. It takes longer to aim the shot, but what you pick is always in focus.
I think there have been many good suggestions above, without changing any settings on the camera, I'll recommend this:
Try centering your subject in the frame, then half-press the shutter button, and hold it. Then re-frame your shot as you like. Press completely to take your shot.
I personally don't like to focus and re-compose, but without being able to choose your AF point, that's the best you can do to avoid what happened in your example, other than increasing your DOF by using a smaller aperture as recommended by others.