This is extremely minor, but it confuses me every time I go to add a site. Here’s a screenshot of the detail I mean in the web client, on a folder called “read-eventually”: https://www.dropbox.com/s/o5y0rman6zp…
The left-hand icon opens an actions menu (mark as read, add site, etc) but looks like an expand/collapse widget. The right-hand icon expands (unfolds) the folder; when I go to add a site I always get trapped into thinking that’s what this “plus” button should do.
I have a suggestion for more traditional icons: use a cogwheel for the left-hand menu (standard for tools/actions) and use the current left-hand icon (expand/collapse) on the right (as is the case in the iphone client).