English is linear. The English language is 1 dimensional (linguistically and literally). Words are just abstract representations. If I were to say "eat" to someone who didn't know English, they would have no idea what I'm talking about. But in ASL, they would have an idea that the word is related to food or eating. These are the signs that are that sign because they LOOK like the word. The only thing in the English language that comes close to that are onomatopoeias/onomatopœia (words that sound like the sound they describe: Plop, Zoom, Bonk, Tick etc.)
...Make sense?