I’ve gotten myself in the habit of checking definitions on words I have any question about that I come across online. It’s just too easy to assuage any doubt. I knew that ephemerality was referring to the temporal or fleeting nature of things but I had a little naggling doubt about it so I marked it and told Chrome to look it up.
My personal opinion is that the below definition is useless.
noun ephem·er·al·i·ty \i-?fe-m?-?ra-l?-t?, -?f?-\
Definition of EPHEMERALITY
1 plural : ephemeral things
2: the quality or state of being ephemeral