It looks wrong in several ways.
First of all, each pump discharge line needs its own check valve.
If they are sharing one after they join up, the pumped water can just run up to the wye fitting and back down again, because the weight of water being held by the shared check valve is causing resistance, and some or all of the pumped water will take the easier flow path right back into the pit.
The main pump might be able to pump some water past the check valve, because it is stronger, even though some water is short cycling right back into the pit, out the bottom of the other pump.
Secondly, it looks like your main pump is not supplied with a 2 inch discharge, it is a normal 1 1/2 inch pipe down in the pit.
The discharge pipe only changes to 2 inch pipe several feet later, after the shared check valve.
If the discharge fitting of your main pump is 1 1/2 inch, it does not need 2 inch pipe.
Also, each discharge line needs a small approx 1/8 inch hole (or slightly smaller) neatly drilled into the side of it, down low enough in the pit that water will spray out of it but will not splash out of the pit.
And the angle of the hole should direct the water slightly downwards, to minimize splashing.
And the holes should be placed so as not to squirt water onto a float switch.
These little holes allow the water in the lower end of the pipes to drain back into the pit, so the pumps can more easily prime themselves and start pumping.
It is better if you ditch that pit cover, and have both pump discharge lines come out of the pit at least a few inches, then a high quality check valve on each, then a few inches more straight up, then put a 45 elbow on one, and join them in a wye going to a common discharge.
I usually put the backup pump on the 45 elbow line, but there is debate about which way is best.
Use a heavy rubber coupling (not a check valve) to join the upper end of the common discharge to the existing discharge line, so you can more easily take everything apart as needed.
You can get a plastic sump cover with a slot cut out of the center, which will slide right over your new double discharge pipes.
So basically, everything needs to be totally redone.