There are lots of operatic examples - if you want to stretch that far!

Just a few random examples:

Hindemith's whole opera on "Mathis der Mahler" (the German 16thC.
artist Mathias Grunewald)

Cavarodossi (Puccini's "Tosca") was a painter - his 1st Act big aria
"Recondita Armonia" is sung while he is painting a portrait of the Virgin

Marcello (Puccini's "La Boheme") is also an (unsuccessful!) painter -
working on his "Crossing of the Red Sea" and the drowning of a Pharoh

Tamino (Mozart's "Magic Flute") sings his big Act 1 aria "Dies Blidnis
ist bezaubernd schoen" (O loveliness beyond compare) to a beautiful
miniature portrait given to him by the Three Ladies and which he
then carries around with him.

There's also a portrait of Antonia's mother which switches back and forth
from a painting to her ghost in the Antonia Act of Offenbach's "Tales of
Hoffmann").

Must be lots of others?...

Patrick Boylan