Very exciting idea - imagine that :

you're looking for a vector application for Linux Debian
you fire up Synaptic then filter through the vector applications read the description and so on ... but then you have this little screenshots for each application. It's brilliant, it's new (then ending my little example considering all vector application you wisely choose inkscape because it rocks).

Okay, back to earth now, this new project is still in beta phase read this for more detail - Basically the current status is all about gathering those precious screenshots.

So if you have some spare time post a few screenshots today - it's easy to contribute
check the list of packages without screenshot and then Just launch your favorite application - type 'gnome-panel-screenshot -i' from a terminal box then select Grab the current window (just like below)
It currently takes less than a day for your contribution to be reviewed/checked.

As the developer said on the project page "Whether you are a developer or not - we appreciate if you upload screenshots."