The map is color coded by trend, the size of the boxes represent the size of the market. You can see that large swaths of LA have lost a lot of value, but there are enclaves, especially along the coast, or around Pasadena and Arcadia, that have held up pretty well. Manhattan Beach and Hermosa Beach are actually still going up!
I think it's interesting to see how the crash hits different places in different ways, and it mostly makes intuitive sense to me. But I'm not convinced that the beach cities have completely escaped. In fact I'm betting that over the next year there's a second correction that hits these areas. They may not end up taking the same percentage hit, overall, as the rest of the region--the prices here are high because people actually desire to live here--but there's still a bubble mentality to the real estate near the water, and at some point it's going to have to pop.