Trouville is only on the opposite side of the river or Deauville. They are almost like twin cities. Deauville is well known for its casino and its festival of cinema. Trouville is less bourgeois than Deauville, more down to earth while Deauville is like the Cannes of Normandie with luxury brand shops in beautiful typical houses : Hermès, LV, i even saw Balenciaga bags displayed at the Printemps departement store there which is also in the cute typical town houses.
& now Deauville's shops, no Balenciaga shop there but i saw some at the Printemps store.