Along with the music and narration that accompanied the clips of La Jetee, this helped take the viewers on this cinematic time travel of the film. Even without actual film takes, photos that captured the moments were used to give the audience a visual of what the narrator was saying. Cinematic time travel has evolved tremendously throughout the years. Ways to draw the audience in and bring them into the sense of time travel has used much technological innovations to create the most realistic way possible. One film that used cinematic time travel is X-Men: Days of Future Past. Throughout the film, the storyline follows the character of Wolverine who travels back in time to change the course time that leads to destruction in the future. Viewers get a sense of what is past and future because of jump cutting between the two times. We see the characters in the past and the events that unfold and placed them on the path of who they were meant to become in the future. Very different from Le Jetee, X-men uses more technical methods to recreate the time travel. Many other ways to include time travel in a film have been used in films like Back to the Future. Ultimately, early films introduced a new discovery that would later lead a breakthrough into the world of time travel.
Here is the trailer to X-men: Days of Future Past