Despite the optical illusion of the 2-D pix, Alembics tailpieces tend to slope down in the front (i.e., the edge facing the bridge) like a wedge. For example, the famous Alembic bird tailpiece, which would appear in photos for all intensive purposes to be level and flat (when looked at from above in plan view), is actually a wedge in cross-sectional view (i.e., when viewed from the side)