"Does the anonymous staff member also add ketchup (or, shudder, mayonnaise) to chips before serving them? What about cream - (s)he doesn't add it to the crumble before it gets to the table, I presume? Jam on scones likewise - what sort of cafe would sell scones with the condiments pre spread?"
I was with you until the crumble. Crumble, especially of the apple variety, should be served with custard surely?
Also as for serving scones with condiments pre-spread, while it does seem odd I have been to at least one or two establishments where they do exactly that. My theory on the reason for this is that it prevents them becoming offended by your choice of order for the jam and clotted cream. I'm a butter/jam/cream sort of chap, but I understand there is a bizarre fashion for butter/cream/jam or in acts of clear insanity just cream/jam or jam/cream and no butter at all.