The flavortext and the enumeration under some of the famous paintings like the Mona Lisa suggest that we have to take the "nicknames" of the artists, or common abbreviations of their names. In order, those are (familiarly):
The Beach Hat by BOB HENRI (or ROB HENRI)
Serenade by JUDE LEYSTER
W.B. Yeats by GUS JOHN
Scène de Naufrage by THEO GERICAULT
Twilight by LIZ PEYTON
Nighthawks by ED HOPPER
Mona Lisa by LENNY DA VINCI
The Persistence of Memory by SAL DALI
Among the Sierra Nevada, California by AL BIERSTADT
Taking the highlighted letter from each name gives us BUSH IDYLL, a painting by Frederick McCubbin. In accordance with the rest of the puzzle, the answer is his nickname.
I wrote this puzzle alongside the metapuzzle for this round before presenting either of them because this is a rather odd feeder answer.