On evolution and the "physical Baldwin effect"

This may be obvious to a evolutionary scientist, but the other day I was thinking that perhaps evolution is not just about random mutations that are "selected" by environmental pressure: perhaps a mutation provides only a slight phenotypical advantage, but this mutation may have other phenotypical effects, perhaps visible but not providing any advantage (or disadvantage). 

Now, the interesting thing is this: such phenotypical expression may end up being associated (in the minds of the animals) to the fact that the individual does have a true phenotypical advantage. Then, an unrelated expression will effectively have some reproductive advantage, and genes that enhance this feature (even if these are not the ones providing a direct advantage) will end up being selected for. 

I am thinking for instance about the colored shapes of a peackok's tail... to generate a form in the shape of an "eye", there must be a complex process of diffusion during the embryonic development. This process produce something looking like an observing eye (which may provide some survival advantage), but also has other distinctive features (like the "flow lines" that are very beautiful). Perhaps after several generations, these flow lines become also attractive for females because they "come with" the eyes. 

This reminds me of the "Baldwin effect"... and perhaps it is exactly that but for physical traits.