We've talked about The Block Metaphor before, and I agree that it's really useful for representing some of the ways language works. The things I like about it:
It accounts for the differences in interpretation that different readers obviously have. Each reader(listener) has a different set of blocks (given to them by education, imagination, experience, previous reading, etc.) that they use to approximate the writers'(speakers') blocks, which are, in turn, different from anyone else's.
It gives the reader a lot of credit. Instead of being a passive recipient, the reader has the freedom to interpret and build their own structure. Often, readers will create the same structure, but any semanticist will tell you that almost every sentence is ambiguous - one reading is usually just excluded for convenience, but we can choose it if we feel like being impractical.
It illustrates many different types of exclusions that might lead to misunderstanding. For instance, two people who speak different languages have completely different sets of blocks, and it's likely that they will never arrive at the same structure.
It allows an understanding of "mistakes" as a simple difference in blocks. A native speaker of Japanese, for example, has different phonetic blocks than an English speaker. When she learns English, the Japanese speaker maintains use of some Japanese phonetics, as in the classic L and R switch. Our metaphor allows us to say that L and R are viewed as the same block in Japanese, or that the rules Japanese speakers follow to choose between the two are different from those of English speakers.
It demonstrates how puns, misunderstandings and double meanings arise when we have two blocks that look alike.
I don't think that's a complete list, but it's enough to explain why I like this metaphor so much. I'm also interested in the way our access to different sets of blocks can be limited. Usually, we don't have a block just because we don't know a concept or word - jargon, for example, can be used to exclude people who haven't learned certain blocks. But access can also be limited by authority, including social authority. Consider all the hundreds of times you've been stopped or discouraged from using a certain block because it was profane, not politically correct, wrong, inappropriate, too smart, too dumb, not funny, not serious, mispronounced, and so on. There is, in each of these cases, some authority making pronouncements about what is excluded, and those authorities should be considered, too.