When two or more guys are hanging out and a hot girl walks in, one might exclaim 'Boob Shotgun!'. This is related to two people walking to a car and one calling 'shotgun', therefore claiming the passenger seat. Exclaiming 'boob shotgun' means to call dibs on a girl, especially of the boobs.
The ability girls and women have developed to hold several items at once in one hand. The skill has been developed due to the lack of pockets in women's clothing.
I thought she'd need multiple trips to carry her phone, keys, wallet, and Starbucks to her car since she needed the other hand to open the door, but she used her impressive girl grip to carry everything in one hand.