Hi @tamatoa,
LOA is a commercial version of magick. Way before “the secret” you could find all LOA techniques in many different metaphysics-manifestation-occult books and ancient spiritual teachings. They simply picked few techniques, formed a “product” around it, and introduced those techniques as a principle called the law of attraction.
The LOA in my opinion, got absolutely nothing to do with Angels or any spiritual beings. They do not operate according to that “law”. On the other hand, emotions are spiritual language. I personally believe, that emotions are one of the languages that Angels, Demons, and all kinds of spirits use to communicate with us. Because they bypass our conscious reasoning mind, the monkey mind which blocks our access to the consciousness of spirits. If that’s what Rose Mannings mentioned in her book, then I completely agree with her.
Emotions are also energy that the universe as a whole can understand. This idea is in the LOA teachings but the law itself is questionable, to say the least.
In her book “magic and law of attraction”, author Lisa Chamberlain ( Wiccan ) explains the connection between magick and the LOA. And how this law is actually very small part of the Hermetic philosophy, which is outlined and explained in the Kybalion.
The emotional concentration is a fundamental principle in occult and metaphysical science. Probably the authors that I learned a lot from, regarding this principle and many more, are Joseph Murphy and Neville Goddard, both were students of a Jewish kabbalist named Abdullah. All their knowledge, which later became labeled as new-age “subconscious power” stuff, is originally pure occult knowledge.