Configuration of endocyclic double bond in Vitamin A
The endocyclic double bond of vitamin A has a (Z) configuration. Here’s why:

First, let’s determine priorities of the atoms connected on the top side of it:


C


C (ring)
C (methyl 1)
C (methyl 2)

C


C
(C) (ghost atom; due to the double bond)
H



So the ‘ring side’ — the atom on the left in the way it is drawn at the moment — has a higher priority than the side chain (C at (1.3) beats H at (2.3)).

What about the bottom side?


C (ring)


C
H
H

C (methyl group)


H
H
H



Here again the ‘ring side’ has a higher priority than the methyl group: (1.1) carbon beats (2.1) hydrogen.

Both left-hand sides have a higher priority than their corresponding right-hand side. Thus, the double bond is (Z) configured.