The term is used in biology when two organisms live together for mutual advantage: like the e.coli bacteria in your stomach. They need you and you need them.
I tried to extend it into a larger concept, with the tardigrade, which are usually found in ponds and puddles. They're resilient little microbes that you can dry out, and leave for weeks and months, maybe years, then get them wet, and they'll start swimming again.
When I painted the whole thing I was thinking about mortality, symbiosis, and I kept sticking weird Easter Island statues in all my artwork back then .