Do we assume our readers know the works we’re analyzing or not? Both: Summarize the prior claims and describe evidence both for (a.) readers who do not know these works already and for (b.) readers who may know them but might not remember them clearly or might not see them in the same way that you do. Use summary and description (forwarding) to highlight what you see in the texts (the images) that we might not have noticed or thought about in the same way.
How much detail is too much? Err on the side of too much detail. Academic readers generally want to see you carry out your analysis of evidence in far greater detail, with more nuance, than you are accustomed to, especially from most high school writing. Again, even if I know the work, you are pointing out details I may not remember or may see differently.
Are we allowed to have an opinion? Yes! You can’t write this paper without one. But note that opinions are necessary but insufficient to the task here. You must develop your opinion into a viable claim by setting it against other possible claims and other possible interpretations of the evidence at hand.
Are we allowed to use “I”? There is no rule against it in most analytical essays (this is always an editorial decision, not a rule). But you want to consider what purpose you have in using it. If an statement of “I believe” is not followed by logical and detailed analysis of evidence, then the “I” is at best, meaningless distraction, or worse, hubristic assertion. But if you use first person to more accurately represent your own perspective as a viewer of the images—in order to provide evidence of at least one viewer’s response—then this could be very useful. It can also help clarify your goals in the essay or the reader’s place in the essay (“I don’t want to suggest that…”; “But now we have to consider…”).
Do you have an ideal paper in mind? Not exactly. But here are some basics regarding structure: introduce the problem or question and the essay’s agenda (perhaps its central claim); provide a map of the essay, indicating where it is going; organize the essay logically, with each paragraph’s role clear and each building towards the whole; use rhetorical cues to guide us through the essay; conclude by moving beyond mere restatement of your claim — point towards broader significance, relevance, or further implications of your claim.
Do we need other sources? Probably, but restrain your research to the merely factual, and just enough for necessary context. This is not a research paper. Best to draw on academic textbooks, encyclopedias, or books that give historical overviews or reliable, factual narratives of the relevant events, people, or technologies you needed to understand in order to interpret the object.
Is Wikipedia a trustworthy source? Sometimes. It depends on whether the people most knowledgeable about the particular thing you’re interested in go to Wikipedia to write about that thing. This is true of any number of popular culture phenomena (just sample any reference from Lord of the Rings, for example). It is often not true of historical subjects, though sometimes you find a good factual summary or biography that is amply sourced–this may be true for subjects related to major wars. But academic historians don’t (yet) routinely go to Wikipedia to write encyclopedia entries. For this project, it would often be better would be to use GW Libraries to find academic historical encyclopedias or textbooks for these contextual facts. (We’ll deal with historians’ arguments and interpretations later.)