@SheWoreYellow
Looks like a standard 6’x6’ panel to me. The OP says she can’t see over it.
And of course you can paint the other side of their fence. It’s protective too. You don’t just leave it.
What does everyone else think should happen?
Its illegal to paint someone else's fence.
If it was OP fence just on its own they are not allowed to paint the side facing them without her permission, not allowed to attach anything like flowers or hanging baskets either without OP permission. Thats the law on boundary fencing.
They have put up their own fence in their own property boundary on their own land which they are entitled to do, tough shit if its looks horrible for OP, so long as its no more than 2m otherwise they need planning permission. Its also not a boundary fence. If OP paints it she could be charged with criminal damage its not her property.
Your advice is 100% wrong.