I have a sneaky suspicion the photo isn't level and makes the ice look steeper than it is (the background rock outcrop doesn't look right, for instance).
Must resist temptation to vote 9 instead of 10. :-)
Huh, well I never! I used two hands and was leaning back comfortably on my belay, so for what it's worth, it's at least as level as any other picture I'd take from a comfortable position. I measured the angle as well by making a triangle, and it came up as 51.2 degrees. So judging by the advertised angle of the climb, I decree a margin of error of 1.2 degrees :-).
The only other proof shot I could find was this one
The rock outrcop at bottom right is the same one as in your photo and the snow hump on the mountain fall line directly behind it is also the same (this snow hump has a little thumb of rock to its left in your photo). I note that the image sourced above is level for sure. This photo also shows the hump I'm talking about at dead center.