This is such a unique take on exploration, fantasy, and wonder, especially regarding dragons. I think so many of us are so desensitized to dragons in media, as they become maids, lolis, harem members, otakus, cannon fodder, etc. So seeing a dragon that operates on such a scale like this, where it's so big that its inside is essentially a brand new ecosystem, is such a fresh concept.
And I love how it gives the commander, someone who's clearly been overworked, a chance to finally experience simple joys that she didn't get to have as a child. I'm sure that's a sentiment many of us wish to capture; that feeling of childlike joy and whimsy.