Joke Collection Website - Joke collection - What does this picture mean? Where is the joke?

What does this picture mean? Where is the joke?

This picture shows the outdoor temperature of the vehicle, showing MINUS 4 degrees Celsius, but the owner regards this sign as a villain going to the toilet and a minus sign as a toilet? The Arabic numeral 4 is regarded as the squat body of the villain, and the symbol of 0℃ is regarded as the head of the villain, which is the punchline.