안다 is holding someone or something in your arms — hugging a person, cradling a baby, carrying a pet. In every line here the manner word is 이렇게 'like this' or 어떻게 'how', because someone is demonstrating or asking: 아기를 어떻게 안아요? 'how do you hold your baby?', 이렇게 안고만 있으면 그냥 끝나는 아이거든요 'this one settles as long as you just hold it'. 꽉 안다 is hugging tightly, and 안아주다 is hugging someone for their sake.