If you installed one of the browser extensions, you can select multiple photos to download by a simply drag and drop method described below.

1. You will be given a window that has your files from your computer on the left.  Select the directory on on your computer that contains the photos that you would like to upload. Your photos will then appear in the top window on the right.
2. To select the photos you would like to upload, click (hold down the mouse button) on the photo and drag it from the upper right box to the lower right box.
3. Once you have selected the photos you would like to upload, click the ‘Send’ button on the top right of the window.