2. The image could depict Yog-Sothoth smiting an unnamed city, as related in the Necronomicon. The passage from the Necronomicon quoted in The Dunwich Horror states that the Old Ones "crush the city" invisibly. Here, a city is clearly being destroyed by an unseen entity.
3. The image could depict aliens using a laser beam or nuclear bomb to destroy an ancient city. "Ancient texts" like the Mahabharata make reference to terrible weapons that either use bolts of light or strange arrows that ancient astronaut theorists assure us are actually laser cannons or nuclear weapons.
Taken out of context, we could make a case (not a good one, but better than most ancient astronaut theory claims) for any of these explanations. But context matters. Number 2, for example, can be ruled out once we learn that the image in question was actually published in 1709, long before Lovecraft wrote The Dunwich Horror.
The actual answer is neither no. 1 nor no. 3. This drawing is a fictional illustration of a lightning strike created to illustrate the lightning section of Franz Reinzer's Meteorologia philosophico-politica (1697; 3rd. ed. 1709). The artist is known by name: Wolffgangus Josephus Kadoriza. The purpose of the art and the book it is found in is also known: The images were designed to illustrate the power of natural forces to compel the Habsburg emperor, Joseph I, to follow the author's policy prescriptions to deal with disasters such as lightning, comets, etc.
Out of context, such a purpose is not clear. Indeed, no one would immediately identify this picture as an attempt to influence the Holy Roman Emperor's political policies. By comparison, the alien explanation seems much simpler and more correct. That is why context matters in evaluating art and literature.