Gallery Image Resizing
Enter a number of pixels - your original uploaded images will be resized to fit a square with this amount of pixels. Try values like 400 or 500 to make sure your gallery displays nicely on a small screen. Students can click on the picture to see the picture in original size.
Enter 0 - images you upload do not get resized. The original image is shown.
This setting only affects the image displayed in the main window, not the thumbnails. When you change this setting on an already created gallery, all the resized images will be deleted and the recreated with the new size.