When we connect a line between the ball joint and the control arm bushing and project it across the plane both for the upper and lower control arms they will usually intersect at some point. This intersection is an instantaneous linkage center. If you do the projection in the front view the instant center defines the camber change rate, part of the roll center information, scrub motion, and data needed to determine the steer characteristics. If you are working with the side view, the IC will define the wheel fore and aft path, anti-lift and anti-drive / squat information, and caster change rate. As with any three-dimensional object, three orthogonal view are possible ; because the third view(top view) is approximately along the single (ride) degree of freedom it contains little useful information about the path of the wheel