The relation of Thomas precession to Ishlinskii's theorem as applied to the rotating image of a relativistically moving body

It is shown that for a solid body following a curvilinear trajectory its rotation angle due to the effect of the special theory of relativity (Thomson precession) is numerically equal to the rest-frame-observed solid angle through which the body-fixed axis turns as a consequence of the rotation change the body image undergoes due to Lorentz length contraction and the retardation of the light emitted by various portions of the body. In classical mechanics, the same relation connects the solid-body rotation angle to the actual solid angle that the body-fixed axis describes as the body performs a conical motion — which is a consequence of Ishlinskii's theorem.