Photos can be old or new, and be of any subject as long as they are clean and appropriate for all eyes to see. How much detail you give in the caption is entirely up to you. Please don't post random photos that you find online.
Everyone is getting excited about having a baby in the family after such a very very long time without a little bundle. My DIL made this lovely sweater (such a nice change from lots of pink). Isn't she talented? My son selected the bunny buttons:)