…It seems like it wouldn’t really matter.
A: Actually, this is mostly unnecessary. There used to be a rule where one could take things out of the top three cards, but that card has been replaced in all current versions with this one, which is more liberal. That said, there is a promo card which allows you to take the bottom card off the discard pile, so it would matter if you were playing with the promo card Composting. Hmm.
In EcoFluxx, the Action Scavenger lets you look down through the discard pile and play the first Keeper you find. Anyhow, you could look at the other cards in your deck, and see if this is going to matter for the version you’re playing with. It’s a matter of logic.