Sometimes the white space, or the negative space speaks more than the touch of a designer's pen or mouse. Smart designers work not only with the stroke of color, but also with the empty space around or in between it. It amazes me sometimes what logo designers achieve by designing around the negative space. I've selected some very smart logo designs posted here on The Logo Mix that make you understand more than you can actually see. In those cases what you don't see is what you should actually get. Some of those logos we are able to understand quickly being more "in your face", while others, even if they seem obvious to the trained designer's eye, they are harder to get from the first glance and take a longer time to stare at them to see everything the designer has to transmit.
What you should see: the "J" letter
What you should see: the dog
What you should see: the bomb
What you should see: the "S" letter
What you should see: the coffee cup
What you should see: the bear nose
What you should see: the sea horse
What you should see: the house
What you should see: the dog head
What you should see: the pelican
What you should see: the spoon and fork
What you should see: the musical note
What you should see: the hourglass
What you should see: the guitar
What you should see: the "S" letter