When my cats are home alone, if someone drives up and opens their car door, they get inside. They also leap into moving strollers (with babies inside). Who knows what they'd do if someone came to the door (sigh)
The story that the originator of this picture gave is that a random stray cat jumped into their empty firewood box, then freaked out. Maybe the story is made up, but still a hilarious picture of the special relation between a cat and its box.