Hi, @mclarke !!
I had never properly tested this method myself before, so your question gave me a good opportunity to give it a try just now. The conclusion is that it is indeed possible. There may be an easier way than the method I tested, but for now, I’d like to share this approach with you. 
What you’ll need are a slideshow repeater and a flexbox. Both are standard elements available in the Wix Studio editor. First, place a slideshow repeater on the page. Then, delete all the default template elements inside it, as they won’t be necessary. Once it’s cleared, insert a flexbox element. For example, a flexbox with three boxes arranged horizontally would work well. You can add more boxes if you’d like. 
Next, place an image element inside each box. Resize the images to fit, then click the stretch button in the top-right corner of the image element so that it fills the box nicely. Repeat this process for each box. 
Now, create a collection for the repeater. Let’s make four fields, all of them image type: background image, content image 1, content image 2, and content image 3. After creating the fields, add two sample items for testing, and assign images to them (you can choose from the Wix image library, for example). That completes the setup of the collection.
Finally, connect this collection data to the slideshow repeater using a dataset. In the editor, create a dataset for the collection you just made. Then, connect each element (the slideshow repeater’s background image and the three image elements inside the boxes) to the dataset fields. As the last step, go into the slideshow repeater’s settings in the editor and toggle on both Autoplay and Infinite Loop.
With that, you should be able to achieve exactly what you’re aiming for!
