maths
Looking at it as a simple Maths problem. If descent angle is 3 deg, you need to change body angle by 3 deg to get a level flight path IF the speed was constant. Wind additives to V Approach would have the effect of giving you a virtually constant body angle (for an unadjusted V App, you would have a higher body angle due to a lower rate of descent.)
at the COMPLETION of the flare, the body angle would be higher than required to fly level, because you would have been using additional lift coefficient (angle of attack) to change flight path from descent to level. If you had a speed vector which you could point at the aimpoint during approach and then at the horizon on completion of flare, you would get a perfect touchdown every time, regardless of speed. Every landing technique aims at this trajectory, with different ways of briefing for it, with the addition of the speed decay from V App to a few knots below.
Just my two bit worth