One obvious question that one could ask would be, "how are non-Western peoples portrayed in the film?" The concept of Orientalism, as identified by Edward Said, is that of "a binary distinction between ‘the (allegedly inferior) Orient’ and ‘the (allegedly superior) Occident." Sometimes this might be explicit, but usually it might consist of the portrayal of non-Western peoples as violent, uncivilized, or even just "exotic."
A related question might be, "what stereotypes are perpetuated in the film (or, for that matter, novel, play, or other work)?" A film, for instance, that depicted people from the Middle East or Central Asia as uniformly radical or sympathetic to terrorism would perpetuate a common Western Orientalist stereotype.
Finally, one might ask if a work attempts to "essentialize" a non-Western people, claiming to capture the "spirit" or even the "culture" of a people. This might include, by the way, scholarly works, including those by historians, anthropologists, and others. In the context of film, for example, a documentary about a non-Western (itself an Orientalist term) people might be seen as an example of Orientalism.