It turns out that Yahoo already has this feature. Yahoo's search results are powered by Microsoft Bing, but Yahoo has its own UI and it does a pretty good job. Yahoo uses the same infinite scrolling interface (Google borrowed it from Bing), but things look different once you click a search result. Images occupy the entire page and you can click the small "play" button at the bottom of the page to start a slideshow or just use the "p" keyboard shortcut. There are some cool zoom effects for big images and, if you use a browser that supports the HTML5 fullscreen API (Chrome/Firefox for desktop and Android, Safari for desktop), you can click the "view fullscreen" button at the top of the page and only see the images. You may want to restrict the results to large images.
Yahoo has a similar interface for the mobile search engine and it looks more like the old Google Image Search for mobile. The new Google interface has some benefits if you don't want to see all the results sequentially, but the old UI placed more emphasis on the images. The nice thing is that Yahoo has the slideshow button in the mobile interface, as well.
