The level is for when using a tripod really Ray.
If you want a point to look at to compare in these two shots, look at the dark lines of the ripples in the water, you'll see they are definitely slanted in the first shot but true horizontal in the 2nd.
As a useful hint Ray, try using the little squares inside your viewfinder as markers to fix on points in your picture so you can see if they are level or not. For example, if you have a horizon you want straight, look at the left and right and put the line at the same point relative to your little squares. This will help you get the shots square
Cheers,
Rob