The winterizations valves and total number of, differ between RV's.
You can have only one (which uses internal backflow preventers to keep water only flowing one way).
You can have three, which has manual valves to shut off cold water into the tank, and water from backflowing into the tank via the hot water line, once you open up the crossover valve.
You can also have two valves, like you do. You just have the cold water inlet and crossover line using one valve...and then the hot water outlet line on another valve.
On your system, when the valve handle is parallel with the line, then it's open. Your first pic shows the cold water inlet (blue)line as open and water flowing into the tank. Since the line is open, the crossover(bypass) red line is closed, so no water can flow thru it.
You also have the top valve open, so water can flow out of the tank once it's heated (red lines).
To bypass your system, you just change the position of the bottom valve so water can not enter the tank and goes to the crossover line (into hot water line). Now since cold water is going into the hot water line, it would backfill the tank unless you ALSO close off the top hot water line outlet valve.
This link explains the winterization process, and I edited your pic somewhat to help too.
NO (OR MINIMAL) HOT WATER (Please read first)
In the pic edit below. The first sentence for each valve is how you want it for normal use. The second sentence is for winterization and the hot water tank bypassed so you can add antifreeze to the cold and hot water lines...all explained in the link above.