My graph at I30 Pylons at night with my green lights on:
Down Imaging:

The cloud on the upper half is the baby baby shad, the white dots and lines are game fish schooling under the cloud of baitfish.
Normally I would see what your pic looks like the one BassProJD posted. Your are graphing more shad then the fish you are targeting. If you turn down the sensitivity on the graph, you should start to see whats below, or at least less bait and a bit more game fish and their depths. You really dont want to see the shad there, most are super small and worthless. You want to see the fish and what depth they are feeding at mainly. With SwitchFire, on Humminbird, I can see my minnow or lure below the boat and we can target a fish at any depth it is at. -Or where the school of fish are activly feeding.

Dark red on the bottom half, are sandbass and hybrid stripers. The bigger and redder the fish , the bigger it is.
Within 5 minutes of turning on my lights, this is what it looks like at the side of my boat almost every night, wind permitting.


All you have to say, is, " Carey, I need another minnow". Ill scoop you up a fresh wild caught minnow in less than 2 seconds.

One shad will not give you a str8 red line. Only game fish or 10 ish inch fish. So in JD's pic,, IMO, Id say 90% shad, but I can make out some bigger fish in the cluster mess.....
Disclaimer: watch out for copy cat lights on ebay. They dont work. People have tried to take the cheap way out and only get burned and waist their time.
I got mine form WildCatLighting.com