uhm…how do i make my store/album look like yours?

For albums you will need to create a custom taxonomy-ims_album.php template and use the WordPress feature image.

you may want to change the image size by using set_post_thumbnail_size( 800, 320, true );

to add a download button use

function add_ims_image_tag_buttons($buttons, $imageid, $data){
	global $ImStore;

	$buttons = array_merge( array( 'download' =>
		'<a class="ims-download" title="' . __( 'Download' ) . '" href="' . esc_attr( $ImStore->get_image_url( $imageid, 4 , true ) ) . '" download="'
		. esc_attr( $data['title'] ) . '">' . __( 'Download' ) . '</a>' ,
	), (array) $buttons );

}
add_filter( 'ims_image_tag_buttons', 'add_ims_image_tag_buttons', 10, 3 );

the rest is just css work.