//FORM THE API

photo - Requires either source or data, but not both. If both are specified, source is used.
source - The URL of the photo to copy. This must be a web-accessible URL, not a local file or intranet location.
data - An image file. See File uploads below.
caption (optional, HTML allowed)
click-through-url (optional)

//WHAT I HAVE

           var data = new NameValueCollection
                {
                    { "email", usernameBox.Text },
                    { "password", passwordBox.Text },
                    { "type", "photo" },
                    { "data", tempImage }
                };

//USING THIS

            FileStream tempImage = new FileStream(@currentItemDir, FileMode.Open);

and

            Image tempImage = Image.FromFile(currentItemDir);

where

        string currentItemDir = FolderName + selectedItem;