This trend needs very little explanation.
Streetstyle is dominated by denim these days. Ripped, bleached, coloured, skinny, boyfriend fits, as blouses and jackets. Remember how Britney and Justin attended the red carpet once, both dressed head to toe in denim patchwork outfits inclusing a little denim purse? Google the picture, laugh a laugh very loud, but then take a look below to see how cool double denim can look.