You're right, it does look like a hiway!
. That upper right image is side imaging. The yellow line in the center of the image is the dividing line, the left or right side of your boat. The black between the line and the gold is the water depth between the boat and the bed of the lake or river. And then the gold is the bed and out, towards the bank if you will.
Because the image is gradient in color, that is typically a rise or decline in water level, in this case, and down imaging confirms, a rise in the bed and on that rise is an object. That object is assumed to be a brush pile because you can see the shadow beyond it which shows that it has height. Once again, confirmed by both down imaging as well as 2D. Beyond and below the shadow of the brush, you see those white or gold footballs, they are most likely rocks but not definite, they could be fish but they do not have a shadow beneath them like the fish tight to the upper right of the brush that clearly has a shadow beneath it.
The lower right image, down imaging, confirms that there is a rock beyond the brush just like 2D shows in bright red. Harder returns give brighter colors. Finally.....you seem some red on the down image indicating a fish. I am not sure what sonar this image is from, I believe it could be Lowrance as they include fish identification on their down imaging.
As you can tell by my ramblings, there is a wealth of info and I may also geek out over this stuff.
. End result, cast at that stuff!
