I was just sifting through some old posts and came across the ones I made when I first started watching
Battlestar Galactica. I noticed in the miniseries that the viper pilots all touched a photograph before going on a mission and
I wondered who it was. I forgot to mention that Katee Sackhoff answered this question at Polaris earlier this month: apparently, it's a photo of a survivor surveying the devastation on Caprica after the initial attack of the Cylons, and the viper pilots use it as a touchstone to remember what they're fighting for.
Now I know.