Is this normal? I'm really glad that she likes him but it kind of hurts my feelings because she gets sad when he leaves. I can tell her here comes (insert his name) while looking out the window and she'll sit there and look for him for 20 minutes.
Most Helpful Girl
Every time he leaves and comes back again he's undoubtedly bringing new and different smells with him. It's a new experience for her every time, and yes she can still smell his underlying scent of who he is, but she's going to get super excited about the new smells before she calms down and realizes he's who he's always been.
As far as saying "Here comes ____ " watch your tone of voice. If you say it in a monotonous tone, she'll likely be less excited albeit still curious because you're speaking to her and telling her to expect something/someone. Especially if she's well trained on the "here comes" command / expression.
Remember how she acts when he leaves and then comes back. Hold that imagery in your head, and then YOU leave the house for an extended amount of time and return. I guarantee you it's the same reaction, if not heightened because you are hers and she is yours.2