What kind of filter is that? Can't quite make it out. The nozzle between the pump and filter looks like a way to pump to waste (with no multiport valve) or have additional water pressure around the pad if you need it. But I don't see a valve to open it. What is that on top? Does it actuate it somehow? Maybe another photo a little further back so we can see it better?
By the way .... welcome to TFP!
Good, that caught Pool_Medic's eye. So it is indeed a waste as I thought. I've not seen that kind of top though.