These cans are supposed to contain Beans & Sausages. Being canned goods, you have to think that said ingredients would be suspended in...some sort of liquid. But really, what kind of thick goo could be fit to pour over...beans & sausages? Tomato sauce, apparently. And how exactly are such things Sonic themed?
This may be an incidence of it just being Sonic on the can. These were supposed to be at any grocery, circa 1994.