Some fanart intentionally references the style or content of a well known work of art.
Simon and Garfunkel
Leonardo da Vinci
Mona Leia by Rhydderch Wilson, featured on the back of Snowfire #2
cover art from First Time #40. Spock and Kirk are drawn posing as sculptures by Auguste Rodin.
The Birth of Venus
"Birth of Venus remix" by Leela Starsky, from a 2006 HP Fringeart Challenge
by Tanya Rizutti: "Venus of the Dune Sea" -- from I Don't Care What You Smell #3 (1997)
Spock as "Venus on the Half Shell," artist unclear, from Grope Flashback
by Red_Magicmarker, from a 2006 HP Fringeart Challenge, Ginny and Harry from Harry Potter
Kirk and Spock: "Pieta" by Shelly Butler on the back cover of First Time #46 -- see that page for more
Venus de Milo
"Spock de Milo" from Grope #1, artist unclear
Sergeant Pepper's Lonely Heart Club Band
front cover of The Clipper Trade Ship #12, another example of a riff on Sgt. Pepper's Lonely Hearts Club Band, artist is John P. Rielander