To enlarge photos, click on the thumbnail. To view at Original size, just click on the enlarged photo, which will show the photo enlarged to fit the screen. Click on the screen to enlarge that portion of the photo at original resolution. Click again to reduce.

If you want to save photos to your computer, click the box under the thumbnails of all the photos you want to download. Then click the "Download" button at the top of the album. Pick the size you'd like to download (Original is best)and the photos will be downloaded as a zip file to the folder of your choice.