Dog body language is a soap opera of tiny gestures. If you watch closely, the dog getting licked often lowers their head or exposes their neck. That is a classic sign of submission or trust.
By licking the ear, the other dog is saying, “I am not a threat. I am just checking your vibe, bro.” It is a peace offering. It is the canine equivalent of bringing someone a cup of tea and saying, “Tell me about your day.”
This happens a lot in multi-dog households where one dog is clearly the boss. The boss dog holds still while the other one grooms them. It reinforces the pack hierarchy without a single growl. Pretty smart, right?