The first thing that you know about Safety Last, even if you don't know who or what Harold Lloyd is, let alone what Safety Last is, is the guy-hanging-from-the-clock. And it turns out this is what Safety Last is all about. It's the "money shot."
The idea for the film began with the idea of the climb, based on Lloyd seeing it done for real one afternoon on the streets of Los Angeles. And the reason one went to see the film then, as now, is to see that shot, and how Lloyd gets into that situation.
But though that sequence caps the film, and presents several purple passages, the machinations that set up his character, his character's situation, and the relationships in the film are what surprise the veiwer more than eight decades later. They are likely to both endure as something we can identify with and they are likely to remain a window into another era: We can understand why the characters (and especially Lloyd, who is the closest to a three-dimensional character) do what they do, even if the mannerisms and milieu are at best quaint, and at worst very foreign.
http://www.imdb.com/title/tt0014429/
