Good to know about the number of people! I thought I had read something about "for parties under x people" but maybe I'm wrong. Or they don't enforce it.
I was just clarifying the process about the voucher since it seems as not everybody has actually been through the process. And I know in the past they've allowed you to pick from any photo on your card, where I've read more recently they are enforcing the free picture be the one from the M&G.
And to the OP, photopass+ works the same way