This is another masterful passive-aggressive note because it has the right amount of menace. Somebody took their colleague’s lunch and infuriated them. This must have happened frequently because it forced the victim to take drastic measures. Then it culminated in the message that we can see below.
Imagine the paranoia that the thief felt after reading this note. They probably think that their face will resemble a slice of pepperoni pizza after this. Who knows if it’s herpes or if the victim was just messing with their heads? There’s also no handwriting so they retain their anonymity (via Reddit).