For a long time I have been saying the moves in Siu Nim Tao, or any form, are not specific techniques. They are positions, which represent multiple options and multiple opportunities.
Take 20 Wing Chun instructors and have them isolate the same move within Siu Nim Tao (for example), and you can easily get 20, maybe even 40, different explanations or uses for that move.
Each position is like a single word. In the form, the words are stacked in a primer. As you learn the words, you can begin to combine them into your own phrases, clauses, and even sentences (combinations). However, your sentences have no meaning when you are talking with yourself. The real meaning arises when you are in contact with an opponent. Their moves are their statements to you. You respond. The two of you have a conversation. The meaning of a single word struck in the middle of sentence changes based on the conversation you are having with your opponent. In short, each word requires context. Any given word (move) may have multiple meanings given the context.
Here is a nice video showing some different meanings (uses) for moves in Siu Nim Tao.