I'm using fancybox 2 with the following code (demo here): <a class=fancybox href=http://a.com/bmw-328-manual-2008-black-18-inch-rims.jpg titlebmw 328 manual 2008 black 18 inch rims><img alt=bmw 328 manual 2008 black 18 inch rimssrc=http://a.com/bmw-328-manual-2008-black-18-inch-rims-s.jpg /></a><div class=hidden><a class=fancybox href=http://a.com/bmw-328-manual-2008-black-18-inch-rims.jpg titlebmw 328 manual 2008 black 18 inch rims><img alt=bmw 328 manual 2008 black 18 inch rimssrc=http://a.com/bmw-328-manual-2008-black-18-inch-rims-s.jpg /></a><a class=fancybox href=http://a.com/bmw-328-manual-2008-black-18-inch-rims.jpg titlebmw 328 manual 2008 black 18 inch rims><img alt=bmw 328 manual 2008 black 18 inch rimssrc=http://a.com/bmw-328-manual-2008-black-18-inch-rims-s.jpg /></a></div>As you can see, the first image is visible, the 2 others are only visible when the first one is clicked on, this triggers fancybox to start:$(.fancybox).attr('rel', 'gallery').fancybox({    padding : 0});With the CSS:.hidden {display: none;}A question here addresses something that concerns me. The main difference is that I use words in the file name, alt tag and title tag to describe the item.The title is displayed by fancybox when triggered.I wonder if this would look like spam to search engines, would it?
Should I be concerned for SEO when hiding images?
seo;google;search engines;bing
No you shouldn't concern yourself, it makes perfect user sense.If you want to be nice to those with javascript disabled though you could place a <noscript> element with your hidden images.I would also put the photo numbers in the alt tags, something like alt=Photo #2 of bmw 328 manual 2008 black 18 inch rims