More slider images?

I was able to add extra images by creating slides (such as slide-image-4.jpg and slide-image-5.jpg), and saving them to the theme's images folder with the other slides. Then you open your page.tpl.php file from inside your theme's templates folder, and look for the HTML list containing your slides. Copy the last list item, paste it in as many times as needed, and change the numbers on the pasted slide-images to match your new images.

Keep in mind that additional slides may really add up to a heavy page download, and bog down your home page (especially for users with slower speeds on their devices). As far as I can tell, there is nothing in the associated jQuery that diminishes the file sizes on smaller devices. It a slide is 90k on your desktop, it's the same size on a tiny cell phone. And if you're going for improved search engine optimization, Google penalizes slow loading websites. Don't mean to be preachy, but I have clients who would load a dozen large into their home page if they could get away with it!