Is this smart or goofy??

Ever since we adopted Angel I have been trying to figure out if she is just a goofy puppy or just plain goofy. She is almost 9 months old now and still cannot figure out that the reflection of herself that she sees in the mirrors or the windows at night is her and not another dog or something else. She still barks at every little noise she hears too. Anway the other night I was sitting in the living room on the couch which faces the door to our bedroom. My dd was in our bathroom brushing her teeth and Angel was on the bed (which has a mirror on the headboard) in the bedroom in which the headboard is against the living room wall. I heard her growling at something and then she jumped off the bed and came barreling into the living room, spun and looked at the wall that the living room and bedroom share, then she ran back into the bedroom jumped on the bed and started growling again. I asked my dd if she was looking at herself in the mirror on the headboard and she said yes. So she was growling at her reflection and then tried to look behind the mirror I guess when she came out into the living room. I thought it was pretty smart of her to realize the living room was behind the mirror but still pretty goofy that she just cannot figure out that it was her that she was growling at. Have any of you heard of a dog that cannot make that connection? Usually the first time a puppy sees its reflection they bark at it but not repeatedly. Our other dogs don't even look into mirrors but Angel always does.