At first glance the picture may appear to show a difference between the EFIS and the airplane, but in fact it's a bit deceptive. The camera angle, panel angle, attitude of the plane, and the timing of the photo have combined to create a slight deception to the eye in this 2D photo. At this moment in the flight, the airplane was in a turn during and engine out practice, and a good way to see that the airplane is banked relative to the EFIS is to have a look at the top of the photo. There is a lot more sky to one side of the pic, and a lot less on the other. If you use that reference you'll see that the horizon is relatively the same. The angles of the glareshield, panel, camera, plane and the ground have all conspired to create a small deception. It's hard to tell with a camera shot taken at a moment in time from a back seat the actual view the pilot and co-pilot saw. I was in the plane and have been flying behind the EFIS for awhile and would notice if such discrepancies were true.
I was in the airplane and having flown many hours behind many EFISes I am able to tell when something isn't right. This wasn't the case with this example. Technically, it's a complex discussion and if you'd like to converse about the details stop by the booth at SnF or OSH for as much detailed technical info!
Alex De Dominicis