In my opinion....there is tons of members on this team. I would say do one or 2 day and that puts your thumbnail photo on the discussion page right up front....at least for a little while. I feel more people will come back each day to see what you have, rather than all at once. Once someone else does the same, then your little photo takes a back seat when there is this many members.
If it was a waaaaaaaaaaaaaayyyyy smaller team, then all at once would be fine. Theres lots of people here and your items end up on page 10 before you know it, so I'd say post daily. Just my view on it is all.