In your main store, there is a new page called 'store directory'
You'll need to set it to 'active' or 'published'
Then in each affiliate store, there is an option area called 'store directory' where you can upload your thumbnail (175x175) to display in the directory
Ok - got this to work, however, I don't want the directory to appear on my main store.
I have another store that I manage and would like this store to have a directory. Is it possible to make this store a "Main Store" so that the store directory option appears in "website pages".