So I was poking around looking for more information on how attachment is developed. From what I could remember of other information I found/read/saw on TV, I always thought that infants have very short memory spans. This shortness of memory continues up to about toddlers (from the ones I have babysat over the years).
So I found this page detailing more on a child's memory span as well as specific stages of attachment.
It makes sense, now that I've read it, that there are really two different kinds of 'memory'. There is the memory of abstract concepts, and then there is a physical memory. The most familiar people might be with 'physical memory' is with the idea of 'muscle memory'. When you've practiced a movement so often that when triggered, your body will follow through with the movement/action as if on its own.
Since "muscle memory" does not require a lot of cognitive thought to trigger, a child seeing someone playing with a toy in a particular way could instigate them playing with it in the same way. An infant doesn't think about how to play with a toy, they just do, and if they saw how it was played with before, they'll just follow that lead as it would appear as good as any other.