i think it loads all the images at a same time and this causes grey pictures to appear when the image is not loaded. also i think the images should load sequentially as it appears in the browser. this should be optimized to load the images that are to be displayed before than the rest.
also after the first screen of pictures are loaded. it should load four pictures in a row, not trying to load all the pictures at once. when the user press the key down then the new row is loaded.

i don't find option to display the pictures by albums.