Meaning in perception is imposed by the observer - meaning is not inherent to the impression. The impression is ephemeral, yet the meaning perceived is not. When an exclamation is uttered, the fact of the exclamation is ephemeral, yet it may hold meaning within, such as a move made in a game, or a communication regarding the game, directed at another participant.
In other words: whether you quack like a duck or declaim the infamy of a moral choice made by a character in S/lay w/ Me, the fact that you opened your mouth and noise came out is ephemeral; the specific words you used are also ephemeral, as is the language you used, whether you're a bass or a baritone, and so on. What is not ephemeral is whether you were understood, and how - did you just confuse somebody by quacking, did you just amuse somebody by quacking, did you just acknowledge somebody's creative input, did you just accuse somebody of a bad move in the game? Those are some possible meanings held by the ephemeral act of you saying things. In some other situation what you say might also e.g. trigger moves in a game, such as when you utter a move code in Chess conducted verbally - it is ephemeral that you talked, but the move itself is far from being ephemeral.
Thus, ephemera may or may not carry meaning, either on its lonesome or in context or in conjunction with other ephemeral observations. That meaning may be a technique of play, or it may be something else, only limited by human capability of interpreting meaning into ephemeral observation. Creative Agenda cannot be said to inform and contextualize ephemera simply because ephemera is, by definition, the concrete non-abstract physical reality upon which the actual structure of meaningful communication (and play) rests. If there is a creative meaning to the color of the Chess pieces, that meaning is by definition not ephemeral; the color of the pieces is only ephemeral if it is arbitrary and meaningless in itself.