Since I discussed the basics of Vietnamese "dressings" in my post about cucumber salad, you can take that same principle and apply it to most any Vietnamese salad.
A green mango is tartly sour and if used in a salad is similar to a Thai green papaya salad. Except, whereas the Thai papaya salads use either shrimp or crab, this salad relies upon dried squid. Of course, you can use shrimp or crab if you wish. The flavor you're trying to get with the seafood is that salty, briny taste.
My second-youngest aunt made this salad once with shredded squid and I just thought the amalgam of flavors of sour, salty, sweet, was just so wonderful.