Followed the instructions. Installed the plugin. Attached some photos to the page (which is an ordeal in itself - did it not occur to you that the media library might already contain photos? You're requiring that people re-upload in order to attach, according to the pitiful half-literate gibberish you call your documentation!) and added the [wpg] shortcode. Nothing appeared. You should be ashamed of yourself, launching non-functional, undocumented code on the world like that.