There is a lot of misinformation about therianthropy online, but this video describes mental and phantom shifting pretty well. It applies to otherkin and starseeds too. The only thing she didn't mention is how the senses become more like the alter-self /animal.
Also, physical shifting is denied by therians. There are some who can, but it's rare to discuss or witness.
about a week ago I dreamed about a similar triangle with circles over the corners, and took note of it as being significant. I have no idea why or what it means, but I was drawn to your thread, and my heart skipped a beat when I saw it there! I know very little about starseeds, etc. I've just began to explore it. Please contact me?