Ears Forward Tail Pointed Something Exciting Is Going To Happen
Dogs have an incredibly sharp olfactory sense as well as an aptitude to sense peril where humans cannot. But if no peril is present and the atmosphere is slightly unfamiliar to your dog, they will likely react this way. Their ears will be perked up so that they can better take in their surroundings. And their tail will be held high, indicating that they are intrigued and relishing the experience.
This is great body language to look for while your dog is frolicking with other dogs or investigating a new park. You want them to be inquisitive but also secure and still alert of any peril.