Linear polarized 3D glasses and the physical shape of light waves

Looking into how linear polarized 3D glasses work, I keep getting explanations that boil down to this:

However, I always assumed that a light wave was depicted in diagrams like this...

...to more easily plot on paper its properties like frequency and amplitude. I never thought that light waves would physically actually look like that. I always imagined light waves being emitted in the form of a sphere centered at its source just like sound:

If the latter is correct, then this explanation for polarized filters doesn't really make sense; or do I have some major misconceptions about the nature of waves?