The first is like striking a gong; actively creating a felt sense of metta, and the second is like listening to it.
In the beginning, striking the metta gong may not do all that much; you get some underwhelming little thunks that don’t sound very gongy at all. There’s not a lot of resonance for you to listen to, so the emphasis in the beginning will often need to be on the first kind of intention. This is the emphasis in most metta instructions, which stress simply repeating phrases.
