Dear @eddieperrote
I dont think this is possible without doing some extra coding.
The Project Thumbnail is there, but all the images within that project will not be called upon until triggered by going to that project/page. Some custom coding would need to occur that when either on page load or when a project thumbnail is clicked upon - a call go out to ask for all the image Data connected with that Thumbnail and load it.
I was also thinking a way to trick it would be to use The Element Grid. The first Image of the Element Grid would be your Project Thumbnail and the rest, the images relating to that project. All the image data is called so thats sorted - Then just add some code that 'display:none' all but the first image in the Grid ( your Project Thumbnail ). This way you could have a page of Element Grids that look like a page of Project Thumbnail's and then when you Click further and Lightbox kicks in your can swipe through the images.
This means things would require time setting up and also if there are many projects with many images it may slow the page down depending on size and quality.
I hope these initial thoughts may help you or send you in the right direction - possibly other functions like 'stack' or 'Carousel' can also be manipulated.
Best wishes and have a wonderful day :)
Richard