Laṭīf relates to fineness and delicacy; here it indicates a person of refined appreciation. Mutawassim is an active participle from form V, tawassama, root w-s-m: one who recognizes characteristics from their signs.
PhraseEmphasis
لِلَّطِيفRefined taste
لِعَيْنِ النَّاظِرLooking carefully
الْمُتَوَسِّمRecognizing signs