Consider the case where the owner of a business may pass a rule that none of his staff may wear hats (just for simple uniform reasons).
There is an active vs passive difference there. In that case, the owner is actively passing a rule which prejudices a minority group. In our case, we are sitting back and doing nothing and the default prejudices a minority group. I think that is an important distinction. We shouldn't have to go out of our way to cater to the needs of minorities, we just have to no actively do anything which prejudices them. (NB: While adding the images is active, that's done by an individual. Wikipedia as a whole (or the WMF, if you prefer) not having a rule against it is passive. I guess the individual could be being racist at a stretch, but Wikipedia isn't.)