In reference to someone's job that is considered to be the "good life" or they do very little for the amount they get paid.
She does absolutely nothing all day and gets paid for it. That is definitely a Gravy Train with Biscuit Wheels.
When a woman bends over and her legs do not touch at the top and you can see her pussy lips under her ass cheeks.
When Nikki bent over and the sun blared through the window, you could tell she had no panties on...because you could see her beautiful moon pie.