During a lovely spring day, Laura decided to take her dog for a walk in the park. The sun was shining brightly, and the flowers were blooming all around. As they strolled along the path, Laura noticed that her dog was especially lively, wagging his tail and barking happily at the squirrels in the trees. Suddenly, Laura spotted a group of children flying colorful kites. The sight was so joyful that it filled her heart with happiness.

In this passage, the word 'lively' is used to describe Laura's dog. What does the word 'lively' mean in this context?