Since dogs do a lot of their communication with their bodies, it's almost like communicating with someone who 'talks' using sign language. Looking at them is then the equivalent to listening to them, because that is how you receive their signs to understand what is being 'said'.
It might also be part of why they want so much attention. It is how they 'talk' to us, so they want us to 'listen' to what they have to say. Unlike human sign language, dogs only have so many possible signals they can send, so it can be difficult to pick up on their message. This makes it even more important to observe the dog to start to understand when and why he uses certain signals or combination of signals. These aren't just calming signals, but things like certain body positions, the angle/orientation of his ears, what his tail is doing, and so on.
Once you start to put together a mental profile of sorts, you start understanding his "accent" of sorts on the universal dog communication. Sometimes, even other dogs have to do this since no two dogs are completely identical, including in their communications.
But observation is also for lots of fun things too. You can see what things will make him happy and which things he really enjoys. You can use this to have fun with him, come up with games based on these things, or see what would be really rewarding during training.
I've found some really unusual things about Wally this way. For example, is love affair with Dora the Explorer. He totally gets fixated about the show when it's on. He whines at the tv until I let him go up and "say hi" to his "girlfriend". I've used this as a reward during training to help him lay calmly beside me. If he's lying down, he gets to see the show. If he doesn't, well - Dora suddenly "disappears". I'll ask him to lie down again, and when he does, she "reappears". Dora likes good dogs LOL.
Other more mundane things such as which tree he likes to "leave p-mail" on or which areas he likes to investigate and "read the news" and "leave a message" of his own. Things like this I also use for training rewards.
Observing the dog can also show you his play style when romping with other dogs, which doggy games he'll play (Wally loves to chase and tries to instigate it when he's with a dog he's interested in), and what things he doesn't like in social situations and how he deals with it.
Looking at your dog with a curious and careful eye, you can learn all kinds of quirky and fun things about your dog as well as get a better insight on how he communicates and what's he's trying to 'say'! Have fun with it!