When looking at the following Transavia B737 safety cards, I noticed that after a water landing, passengers who evacuate via the overwing exits should leave the wing at the front, while during evacuations on land they should leave via the rear side of the wing.
It is clear for me why normal evacuations need to go via the rear side of the wing, but why does a water evacuation need to happen via the front side?
Does it have to do with the center of gravity position, in an attempt to keep it is far forward as possible so that the tail doesn't sink? Because in the second picture the rear exits are prohibited from use too.