Ed Emshwiller: GALAXY Magazine October 1952
Illustrator and filmmaker Ed Emshwiller paints 23 science fiction luminaries (plus one alien) on the cover of this 1952 issue of GALAXY Magazine at the great Potrzebie blog by Bhob Stewart. The above small sample shows: Fritz Leiber, Robert Heinlein, Evelyn Paige, Cyril Kornbluth and Willy Ley. This is part of a wraparound cover for Galaxy's second anniversary. Click through the link above to see the robot coming through the door with a large "2nd Birthday" cake. The cover article (sadly, not reproduced -- EDIT: This is wrong. Bhob has posted it! Mea culpa!) is titled "The World of October 2052" by Willy Ley.
Footnote: Ed Emshwiller asked a then-13 year old neighbor of his named Bill Griffith (who would grow up to be the cartoonist behind ZIPPY THE PINHEAD) to pose for the September 1957 cover of THE ORIGINAL SCIENCE FICTION STORIES.
Bhob Stewart has more on Emshwiller here.
at 5:06 AM