first of all, you are so much more interesting than the mobile.
YOU are interesting and she can look into your eyes, listen to your voice, and it's just an amazing sight.
The mobile is interesting in a different way and she might be trying to elicit a response from it. "HEY COO WHERE ARE YOUR EYES"
It's new, the excitement will wear off.
When you speak to her, do you leave gaps in the "conversation" so she can "respond" That always triggers my baby's response. Also, if you end your sentence on a high note, so it sounds like a question she should "answer" it. Our conversations sound like this.
"hello sweet baby, are you poopy?"
(random swatting motions with arms and a ton of mouth & tongue movement before she finally utters the word...) "argle"
"No way, are you sure about that?"
(more random arm movements, then a little bit of...) "oooghlee"
"Are you calling me Ugly? Before you were born, I could brush my hair, yeah- AND my teeth."
(random arm movements, then finally...)
"Well Jeez, lady I didn't ask you to stop- where is my darned mobile?"
OK the last part is a lie.
When she sees someone new she doesn't know, she smiles way more than she does for me. She also smiles when she sees the birds on the fence outside. Their motions are unpredictable (like the mobile) and she hasn't figured out yet how to interact with them.
She was born Dec 2