Well, you made me wonder ... See Seedfork's info below on how to include ATP photos ... but for those who also want to track bloomed seedlings that are, of course, not in the database, there is also a way to get a photo link to them.
I use Photobucket to store bloomed seedling photos for free, and there are many different storage sites available. I enter seedlings' events into the Pod Parent Event list, make notes about them (adding the Pollen Parent info) and then paste in (per Seed's idea) the ATP database URLs to my own photos of pod and pollen parent, as well as the Photobucket URL to the seedling/s.
When I want to see a seedling's photo, I just click the Event's hot-linked URL (in blue type, in the example picture above) and it opens up the photo in a new tab. (Does not work here to click the Event URL in the example photo, so it is just a visual sample). At least then I have access to seedlings right in the plant list entry.
Database!