Cool project and kudos to them for working through the necessary math to calculate sunrise and sunset.
You can see a few more pictures on the "Shop" page [0]. They are hidden behind the "View product"-button. I've extracted a few links and modified them to link to larger images [1-3]. The power supply is connected via a barrel connector as can be seen in image [3]. I guess I would have used a USB power supply instead, just because of their ubiquity.
[1] https://cdn.shopify.com/s/files/1/0557/1513/5639/products/li...
[2] https://cdn.shopify.com/s/files/1/0557/1513/5639/products/li...
[3] https://cdn.shopify.com/s/files/1/0557/1513/5639/products/li...