Just an update - because we didn't discuss it and I have an entry, here is how the initial grouping will work for photos: Each entry will be ranked based on the second gmail says it was received. Tie breaker will be the last set of digits of the sending IP address.
So the first entry has this:
Received: by 2002:ad4:4819:0:b0:6a0:ea06:c69b with SMTP id qd25csp838364qvb;
Sun, 5 May 2024 04:58:30 -0700 (PDT)
it was sent from this IP address:
XXX.XXX.XXX.121
Also, when I send my entry tomorrow, I will BCC all the other competitors received up until then, so you can all see I sent it before midnight (as I'm going to be racing against the clock realistically, as naturally is my style)
Hopefully this satisfies all to produce a fair competition.