Just ask her if she wants to see wires dangling behind the tank.
So you have 2 tunze wire, a wave maker wire, you might also have monitor probes. == > at least 3 - 4 wires.
Algae will also grow at the back where it is visible but inaccessible to clean.
You can put 1st and if really doesn't like it, you can remove it easily.
If you did not put it and want to stick it later, it will be more troublesome and will be more challenging to stick it nicely with water in the tank and limited access at the back.
You should have let her choose the lavenda colour for the oyama Jun ... haha