Compared to your existing wheel, this new wheel will have an inner rim which is 20.7mm closer to the suspension strut. The outer rim will poke out 4.7mm more than before.
The strut shown in the diagram is for show only. Don't worry if the wheel looks like it fouls!
Bear in mind most tyre manufacturers vary slighty from the specs, and that it could be dangerous to run tyres on wheels they aren't designed to fit.