Hypothetical situation:
Witch is standing next to a wall, sends Owl to fly over wall and land on the ground. Witch casts Summon Monster on or near location of familiar.
I know vision isn't shared, but does the link provide enough info for this to happen?
Line of effect is required for spells, so this wouldn't work. Try scrying on the familiar instead (with all the limitations of scrying).
Back to empathic link:
Because of the link's limited nature, only general emotions can be shared.
So by the link you know if your familiar is hungry or feeling sad, but not how far it is... unless it goes further than a mile then the link fails.
However the next line in empathic link is a bit ambiguous:
The master has the same connection to an item or place that his familiar does.
This could be twisted to mean that wherever the familiar goes its as if the master is there. In my understanding this line is meant for effects like scrying on the familiar without having to make a check rather than dropping summons on top of the familiar.