[generic.address]

I got a task to describe how I would design a web service and need to answer it in several sentences.
Would you be able to help me with this or at least point me in the right direction.

The task is the following:
You are developing a new web service that allows its users
to browse and/or upload personal photos and manipulate
them by utilising various imaging techniques (synthesise
two photos together, add effects, make slide shows of
photos, etc.) and share it with other online users.

A user will log in and start browsing to find suitable photos
or upload hislher own photos and apply a number of photomanipulation
tools provided on the site and make it
available for others to see and comment on.

As a web designer, what would be the main considerations
in designing a website for this service?
What would be a
good interactioli scheme and suitable flow of interaction for
this website?
Your answer should take into consideration
how Web 2.0 technology could be usefully used to enhance
the user experience of this service.

How can I plan the interaction 'in words'? I can only describe the layout of the website so it's user friendly & logical...
Any help will be very appreciated.