This is the ordinary polite ending 어요 written and said as 어여, which makes it sound younger, softer and a bit playful: thanks so much, I have something right after this, what did you do yesterday. It is typed online and used aloud for a cute effect. It is no more and no less polite than 어요, just less serious, so it belongs with friends and fans rather than in a work email.
Register: cute and casual; texting and playful speech