It's dependent on the sight lines.
A well configured space will allow the electrics that have units serving as
Bax, to be masked from audience view with a
border/
teaser. If done correctly, and if the theater sightlines cooperate, your back light does it's job of lighting what you want lit while not being seen. This is a factor of front row seating distance to the performance area, enough pipes to hang a
border in the right place as well as being flown to the right height, and electrics well placed as well as flyable.
It's sometimes a compromise, and in some spaces, impossible to correct and in some instance, desirable to see the fixtures.
SB