Left image: A person holding a sign that says the letters ACAB. The persons face is covered by a mask, they have black nails and they looks like they are protesting something.
Right image: Person dialling 112 Emergency number on their phone. They have black nails
This is funny because on the one hand this person is rebelling against cops (slogan being All Cops Are Bad - ACAB), but on the other hand they are also calling the cops for help.