I took this photo on the right as a joke to show my friends.
The green truck is a grease truck that picks up grease from restaurants in San Francisco and liquefies the grease with a small gas heater then sells the cleaned output for tallow, soap, cosmetics and even as bio-fuel.
I joke that at this particular restaurant stop, the green truck sells the grease to the restaurant rather than collecting it.
Maybe that is not so funny and a little unfair to people who eat regularly at the restaurant and who are sentimental about greasy breakfasts.