I was looking at the tray card for the Lovin' Spoonful's "Everything Playing" album and laughing at the inclusion of Zal Yanovsky looking through the fence. I don't recall that photo anywhere near the original vinyl release but it got me thinking about other bands who may have paid tribute (whether loving or otherwise) to former members on their covers, gatefolds, or inner sleeves. Two I can think of right now are:

The Rascals on "Search and Nearness" with a distant Eddie Brigati looking through a window and, of course, the Notorious Byrd Brothers "horsing around" in tribute to David Crosby.

Others? Surely an Ian Stewart tribute somewhere?

McCartney II includes a subtle tribute to Paul's old bandmates.

kind of on the subject:

on the CSN "couch" album original artwork, drummer dallas taylor is seen on the back cover peering through a screen door.

after his scathing book, "prisoner of woodstock", taylor was removed form the artwork on the remaster.

In the similar vein of a "negative tribute", the original inner sleeve artwork for the debut solo album by ex-Marillion frontman Fish featured several of his former bandmates as characters near the bottom of "The Hill" (see the huddle in blankets surrounding the small fire). However, the artwork was subsequently revised with masks used to obscure the original faces, as seen here:

According to the liner notes for the Rhino release "Beautiful People: The Greatest Hits Of Melanie", when Melanie attempted to leave Buddah Records and establish her own indie label, Buddah countered by releasing a comp entitled "The Four Sides Of Melanie" which apparently featured images of her husband/manager Peter Schekeryk "with devil ears".

(Would anybody happen to have a .jpg of these supposed images?)