The meme is humorous because it shows a car's license plate that says 'MRS HART', which one might read as 'Mrs. Hart'. However, the text conversation below the picture humorously misinterprets it as 'Mr. Shart'—a word 'shart' which is a slang term for an embarrassing bodily function. This misunderstanding between what is likely intended by the license plate and how it can be humorously misread plays on the similarity in appearance of the letters and the unexpected, crude twist on the name, which may elicit a laugh due to its sudden and jarring nature.