Here is the answer. Movies reflect the values of a society based on history by the manner of dress, hair styles (movies<span> from the 80's), and what is going on in the world at the time. It gives us the glimpse of what it looks like in different era. Hope this helps.</span>
The time in which they are set because this helps the viewer position itself in time regarding the set of values characters might have.
The environment, as a war movie, will probably depict different values in comparison to drama located in a major city of the country.
The theme, as this will help the viewer understand which values will probably be shown. A war movie will probably show loyalty whereas a drama will show solidarity.