A brown shower is often used in dominant games. Lots of people find scat and scat eating very disgusting! So it is a logical consistency that you can humiliate other people with scat in a very intense way! Most of the time a very severe mistress dominates her slave. Sometimes it is a mistress and a female slave or a male patriarch and a (fe-)male slave – but as mentioned before it is rather usual to find a mistress who plays dirty games with her slave(s). But it also relative common that more than one mistress dominates one helpless slave! This way one after another plays with him and defecate at him.
As mentioned before the male victim will be punished for lot of different things. One common reason is that the slave is very stupid / ugly and has no other use than to serve the lady as a toilet slave. The sadistic lady loves it to shit into the mouth of the useless slave and the slave has to eat the shit – like a normal toilet! This way the slave has somehow a value and is happy to serve his mistress(es) while the lady itself enjoys the feeling of having so much power and authority!