Having difficulty getting that slice of pie or cake to slide off the pie server? The reason for using a pie server, as opposed to trying to scoot the thin blade of a knife under the slice, is that it is the perfect size and shape to pick up a piece of pie or a slice of cake. I usually just use my finger (or sometimes the blade of a knife) to push the piece off of the server and onto a waiting plate. The pie slice ejector fills this same function, eliminating the need to get your finger sticky from the pie.
It reminds me of a self-releasing ice cream scoop, where a blade detaches the ice cream from the back of the spoon. When you squeeze the handle, a lever slides forward and releases the pie.
Certainly not the the must-have gadget of the year or anything, but the slice ejector not necessarily a bad idea for someone who entertains a lot and (a) doesn’t want their fingers to get dirty during service or (b) doesn’t want guests to see them poking at the pie/cake with a finger to release it from the server.