The paintings are about the stages of artists' work, the evolution of style, method, meaning.
We fall for an early work-- first sight of a painting or style, first film, first album, first novel. Its flaws, crudities, budget limitations are never more likely to be overlooked than during infatuation. Revisiting work later, particularly when you have a sense of the artist's oeuvre, weaknesses may be pardoned as index of contingency, proof of necessity prevailing against disadvantage.
One obvious metaphor among many: egg, caterpillar, pupa, imago.
Egg-- personal conditions, nature & nurture, involuntary connection with urge to create.
Caterpillar-- fledgling effort, study, cultivation of ambition.
Pupa-- sense of calling, deliberate work, centre of gravity.
Imago-- One's Own Work.
The Beatles: journeyman rockers; sophisticated craftsmen; game-changing wizards. (then retrenchment to earlier forms at a higher level).
In taking on the identity of artist --having taken a seat at the loom-- they weave further the varied carpet of art history. The carpet is there, spread out for all to see; each is free to leasrn from the others, whether the living or the dead.
What serves as inspiration? Having arrived at a personal method, have they been able to modify it...following the realization (sometimes a revelation) that there are other ways as well.