WOW @ the double entendre inherent to this message. Why couldn't they have simply said eating is prohibited on the train? Why have they got to say "DO IT AT HOME"?
Aside: and why do they always say it in the volitional (i.e. "Let's do it") instead of the imperative (i.e. "DO IT!"). It's a rhetorical question, I mean, ... I know it's their cultural way of expressing this sort of rule, but ... is it really
that emotionally devastating to be told by a sign 家でやれ instead of 家でやろう? The latter sounds to myne English ear like a mother trying to coax her 3-year old son into eating his mashed peas. ¬_¬
Normally I love/get a pleasant kick out of Japanese hyper-politeness (both behavioral and inherently-grammatical), but this is one of the few exceptions that always ruffles my feathers.
If it's meant to be a rule, YOU DON'T ASK THE OTHER PARTY IF HE WOULD LIKE TO PARTICIPATE. You tell him, "Do this, motherfucker, or your ass is off the train."