The book, as well as giving some background to each card's main element and a divinatory meaning, also gives a "magical suggestion" for how to work with the card's energy. For Gaia, the author suggests going into nature, connecting with it, picturing yourself as a seed, and letting a song emerge from you.
It being ridiculously early and ridiculously cold when I did my meditation, I didn't follow that suggestion. However, I did a visualisation of myself as a seed, and then growing, connecting with the world around me.
It was a beautiful meditation about the elements and nature in general, as well as my place in it. It also made me think about the "contact boundaries" that make us up as people. A contact boundary is basically where and how we rub up with ourselves, the world and other creatures (they say people, but I'll not be so anthropocentric). We have a contact boundary with our Self, where we distinguish "I" from mere existence. We have a contact boundary with the environment, our skin, where we both have a barrier and also a sensitive tool for feeling all that surrounds us. And there is a "social" contact boundary, where we interact with other beings.
I felt all of that as a berry bush, with prickly thorns to protect my Self from being encroached on or eaten too much. With my roots and shoots that spread into the environment, soaking up nutrients, water and energy, sensing the four elements. And with the berries that I offered up to the world, sharing of myself with the mice and birds and other creatures. I also connected with the worms and bugs who crawled and wriggled in the earth along with my roots.
It reminded me of the importance of protecting ourselves, if we want to be able to serve others - we can't give the whole of ourselves, or there will be nothing left to keep giving over time. And it reminded me to honour all beings, be they people or other creatures, or plants.