sand, ice, lava worlds.... Why I fell all this like they're just jumping into mario bros's worlds? LOL
All of them can be interpreted as representations of the five natural elements of chakra manipulation. Sand is wind, ice is water, lava is fire... That leaves earth and lightning. Whatever Kaguya is doing, it must be relevant to the nature of chakra. This trans-dimensional hopping from one elemental extremity to the other might be the result of some bizarre combination of Space-Time, nature manipulation, and Yin-Yang Release. That would mean Kaguya's control over the natural world is so incredibly advanced that no one but her is able to do what we're seeing in this chapter. She's definitely the mother of nature, in a way.