From Longman Dictionary of Contemporary Englishlook/work a treatlook/work a treatBritish English informalBEAUTIFUL/GOOD-LOOKINGSUCCEED IN DOING something to look very good or work very well The sports ground looked a treat, with all the flags flying. → treat
Examples from the Corpus
look/work a treat• I must say, Gwen, your garden looks a treat.• Don't he look a treat!• I repeated a few times, and it worked a treat - on a window as well.• I bet it works a treat.• As usual, she looked a treat.• It's another first-rate conversion that works a treat on the Game Gear.• Much funnier than Tarzan or Hercules, this works a treat because the hero, Emperor Kuzco, is an anti-hero. 