@rbreich#altText4you a line of five smiling caricatures of:
Mr. Rogers, with his King puppet;
Bob Ross, holding a palette and a brush with green paint, next to a painting of a smiling tree;
Jim Hanson "hand"ling Kermit the Frog;
Rosco Roman holding a green nametag that says "Gordon" (from Sesame Street) in white letters;
and Bill Nye the science guy holding a viol and a boiling flask in his hands.
Text above and below reads: "THANK YOU PBS", "FOR GIVING US HEROES"
It is signed Joe Wos.

(thank you @vfrmedia, @MartyFouts, @moani, @stellarsarah, and @chantaryu2 for piecing this together)