Here goes:

The pizza delivery transaction (that is, the actual exchange of pizza for cash) is a relatively formulaic event, occurring for such a brief duration that no meaningful mindfuck is typically possible. This customer finds a way.

By ordering a bottle of Soda Drank, the customer multiplies the interactional possibilities of the event. Lurking behind a chained door violates the usual proxemics of the ritual, causing an uncomfortable self-awareness in the delivery bird. At this point, the customer takes control by requesting further information, followed quickly by a request for action involving the same object. The fact that "Yes" or some similar affirmation of the format had already been uttered or enacted by the actors added extra weight to the final request, making the potential face-threat of a dispreferred response seem more substantial.

The delivery bird at first complied automatically, but upon hearing the customer say "Pour it, SLUT", the bird realized the previously hidden intentions of the customer. The fact that delivery bird was using its...hands.. to manipulate two objects, such that fluid would spew out onto the surface of another, rendered a vague sexual innuendo.

Thus the delivery bird was manipulated into performing an act with sexual connotations, which were entirely the invention of the customer; furthermore, the bird was forced to realize the connotations and picture them. However, due to the ambiguity of the analogy (how much was homology?), the bird's mind insisted on reinterpreting the image repeately in order to discern just how the action could symbolize sex in the mind of the customer. The possibilities would be:

A. The bottle is sexing the pizza, facilitated by the delivery bird.

B. The pizza is into being humiliated. The bottle is humiliated.

C. The bird is jacking off an imaginary participant with a penis the same girth as the bottle. This role would immediately be filled by the customer himself in the mind of the delivery bird.

So at this point the bird has imagined three lewd acts reminiscent of a three-litre bottle of Soda Drank being poured on a pizza, after being called a slut, which brings him/her to the conclusion that 'C' is the most likely candidate. Then the bird's dirtbag mind requires him/her to visualize it one more time in order to encode the choice.

The bird feels violated, also realizing that by ruining the pizza the customer has asserted that the entire purpose of the order was to lure a delivery driver to the residence in order to mindrape him or her upon arrival.

The comic viewer pauses on the last frame and internally models the hypothetical mindstate of the delivery bird. The momentary dissonance in the mind of the viewer is quickly resolved as direct awareness of fiction is resumed. The realization of the complex nature of the events' integration is similar to solving a puzzle or riddle, so the reward mechanism for apprehending novel things is invoked in the usual way, through momentary euphoria. A laugh sometimes follows.