The 10 degree reference is a few posts back. I believe it is a small angle change to the mount and it would result in the outboard thrust being vectored slightly down some and it would also result in the outboard prop being closer to the water when the outboard was rotated out of the water (hopefully still completely out of the water so you dont get any drag) Some boats have a transom that has some slope. My sailboat transom does not and is similar to what most of us have with the rear mounts that are flush. I get wash over the rear round access plate and some say those are water proof.. but mine is not and that wash results in water in the hull if you are motoring long enough. I once motored for about three hours and probably had 5 gallons of water in the hull. So I added a lexan shield to the motor mount that deflects the wash. After I put this on, I get very little water in the hull even after motoring long distances. In the attached picture (also hosted on FB so it will go away in a couple weeks), the guard is placed exactly where the wash is.
From looking at both pictures, thrust from the prop would need to shoot up at a like 60 degrees or something like that if it were causing the wash. Well.. I have a hard time thinking that is actually happening. The shaft moving through the water at 6 to 8 mph looks way more likely to me to be causing the wash. But.. I could be wrong. Could be something related to using the Honda instead of the Suzuki, could be that the more downward thrust lifts the back end a little and that helps reduce the wash with the tradeoff of maybe slightly lower top end speed. Since I have the lexan guard, its no longer a problem I need to solve.. but who knows.