Good to have that explained. I've disassociated that song so much from the band (it's certainly the one I listen to least) that I didn't even think it had a connection to the cover art. I think of Honeybus as on a par with the Idle Race or the Zombies, and while Pete Dello can get a bit treacle-y, it's usually balanced by the other songwriters in the band. And I think several of Dello's songs are great, just never liked that Maggie song very much.
But I had read in liner notes how it was given extra life due to a bread "advert" (there! i'm catching on now😀) or commercial in England, and of course, you're correct that reference completely passed me by, as I only discovered the brilliance of Honeybus when perusing the Tower Records in Tokyo back in the 2000's...
I still don't know how I made it all the way to this century before discovering that Honeybus were part of the pantheon of great sixties bands.
Getting excited about these vinyl releases!