“Together: choose the photograph of us you both love — and stick it here.”

A set-piece. One table, two pens, the same evening, one joint artefact. These are the pages people photograph.

Why this question

Print it. Glue it in. This is what the page is for. Caption it like a museum exhibit: date, location, what had just happened.

And once you’ve both answered

Then each write one line about what's going on in it that the camera couldn't see.

Answering it honestly

One table, two pens, the same evening. This one doesn't work by correspondence.
Argue about the details out loud before anything gets written down. The arguing is part of the artefact.
Finish in the sitting. A half-built set-piece has a way of staying half-built.

And the house rule, whatever the mode: leave a blank rather than write a lie. A blank can be filled later; a lie sits in the archive forever, and you both have to live with the paperwork.