You use it when your really fricking pist.
for example. "OMG DUDE I DIED IN MINECRAFT imma just hit my keyboard real quick dfxkjlkjhyjbyryres. Damn now i feel better"
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.