I remember reading a really elegant paper many years ago about the Fresnel reflection of a narrow Gaussian beam from a dielectric interface. The paper showed mathematically that since reflection from a dielectric slab is actually a bulk effect from all of the oscillating polarizations within the volume, the outgoing Gaussian beam follows an axis with does not intersect the incoming axis at the surface. Instead they intersect at a point which is a significant distance inside the volume of the dielectric, probably of order $\lambda / \epsilon$ (just a guess) where $\epsilon$ is the dielectric constant.
I can't find that paper right now, but my question is different. Is there any distortion of the profile of the beam? Since the reflected wave from each layer will produce an increasing lateral displacement, when they are added up would a circular-profile incident beam be reflected with an elliptical profile?
I am going to try to generate a drawing for this, but I think the question is sufficiently clear for an optics answer.