(Previously.)
First:
If a star is on the forehead, it can be seen when the bearer looks in the mirror.
If a star is on the back of the head, it can’t be seen by the bearer.
Also:
Another person can easily see a star, whether on the front or the back of the head.
A conversation with someone standing in front of you is different from a conversation with someone standing behind you.
Although:
In the age of mechanical reproduction, a photograph of a star on the back of the head can be easily admired by the person bearing the star.
Just as well as by many others.