So what a rose looks like is stored here, but what it smells like can be anywhere. Seeing or thinking about a rose triggers a search for everything related. "Who's got information about this thing?". Some cells say "I know what it smells like". Another bunch say "I remember pricking my finger on a thorn" and so on.

Where it's stored doesn't matter as long as you can search.

Evidence that it works that way is that the more things you can relate to Y, the easier it is to recall it.