“Fall was about rock ’n’ roll. This is what that girl would be like on the beach,” said Phillip Lim of 3.1 Phillip Lim. “She would be a pirate.” One who dresses, of course, with the casual-cool polish for which Lim’s best known. So she’ll wear those pirate polkadots, but as paillettes on a prettily draped dress. The lace motif, meanwhile, turns up in girlish blouses and vests, some in gold-metal versions for what the designer called “a little treasure.” Rounding out the collection: terrific patchwork pieces — color-blocked denim, spliced knits — and chic shipwreck dresses, with bralette inserts inspired by his new intimates line.