Version: unspecified OS: Linux in order to select the picture to be uploaded to the web, it would be easier to select pictures to upload while browsing the photos as a slide show. Having an "pin" selection like in Picasa, would be great, but do not limit it to the sideshow browser, extend this functionality to the picture editor. Reproducible: Didn't try
You can already do it to tag images with Labels during Slideshow. After that, use Labels tree-view to see you selection and process export. The only pending problem is to be able to use Lablels shortcuts in slideshow mode, which is described in bug #313857 Gilles Caulier