This is actually a very good question. It all started when I realized that for the true justice of the pictures to be shown, they needed to be very large. So I waited until returning from the first trip, the Trans-American Trail, to post all of the images at once directly onto the site using a computer. (I only had my phone on the trip, which I cannot edit the site with.) When I returned home after the trip, I realized that only a few images could be found in the photo inserter. After a long time, clear up past the GEAR UP trip, I finally found out that my albums had been messed up on Google Photos, the photo storage system used to sync photos with this site. After fixing this issue, I still ran into issues with Google Sites accepting panoramic photos. A panoramic photo is a type of photography where you scan a large area and create a very long and thin photo of a very wide camera angle instead of the typical photo dimensions. Since I had a lot of these panoramic photos and Google Sites could not handle these photos easily, I looked for external ways to solve the problem. That is where I came up with the idea to use a Google Doc, a word processor, to house all of the pictures.
At first, the Google Doc idea did not seem like it was going to be a valid choice. After all, Google Docs is a word processor, not an image viewer. It seemed clunky and rough around the edges. However, with some serious rearranging and document editing I was able to get something that I liked. I released a link to a few people to test the document, fully expecting an error of some kind to occur where they couldn't see the photos or something. To my amazement, all of them responded positively, explaining how they liked the setup and how they could finally see the pictures I had posted there. This was thrilling news to me. At long last, I had a method that I liked the setup of and I could still show it to anyone.
There was exactly one downfall to this design: it is an external link. I could have synced the document with the webpage and allowed people to view it this way. (That basically makes a copy of the document and displays it on the site each time the page is loaded.) However, I found that this made the document look poorly designed and actually using it felt very clunky, particularly on cell phones. So, I did not make the on-site version available. That left my only option as providing an external link to the Google Doc.
I am sorry if that external link bothers you. Please know it is currently the best option I have.