Encapsulation

Needs more containers.

Would work as an inheritance joke too "all big trucks extend truck, which extend car"

@Hazarth … which extends motorcycle. (Sitting inside the car)

Now I've realized that even though inheritance is funny, the picture is actually showing composition, which is considered 'the opposite' of inheritance.

@Lensflare huh, you're right, It's closer to composition xD

Inheritance doesn't work here IMO. The fact that what happens to be inside the truck (that car) is something related is just a coincidence - it could very well have been a washing machine, several tonnes of potatoes, or a horse.