Replicating Gallery Thumbnail Tray

[kerns]

I'm interested in porting this feature to PhotoSwipe, that is once a modal is launched, a preview of thumbnails can be shown along the bottom edge of the modal.

https://photos.kerns.co

These are in effect just enhanced "pagination dots" ...they can help tell you how many images are in the gallery and of course where you are in your progress.

I refer to it as a tray bc it should autohide after n seconds. But when visible should itself be an area that could be rapidly scrolled through or flicked so that a specific image could be chosen.

Is this a horrible idea? How would one do it, and @dimsemenov can it be done within the current plugin architecture of PS?