imitation is a concept behind a lot of magical workings.
In an abstract way, words of power invoke both imitation and sympathy. a word/symbol could be said to imitate/sympathize with the thing it represents through its meaning. by speaking or writing the words/symbol, you are performing an imitative act.
transference also keys in here. by inscribing the words/symbols onto an object or area or speaking/chanting them over the object, the sympathy can be transferred to that object or area.