Must be a slow motion ZOT.
I am curious why this would be zotted. Is there a bain ban?
The thing is, these things are portable and put out on Fridays in areas of London that will be busy over the weekend due to people who go out clubbing, dancing and drinking. They are really primarily intended to give people who've drunk too much somewhere besides a wall (or in a few notable recent cases, a war memorial!) to urinate against on their way home - which is far more likely to cause offence.
People know what they are and know not to look if it's going to offend them. It's safer too in many ways - people are in sight.