Alphabet Day 2 - Letter B

(Note: Just in case you were wondering why these posts are coming a little late, I'll explain. They're going to be a little behind from the actual days over here in Korea since I need to wait until my mum actually takes the picture and by that time I'm usually at work, so I will write them sometime in the evening after work during the weekdays, which means they'll probably show up for you North Americans the day after they are posted as.)

May challenge

My mum's picture for today looked strangely familiar to me, but I just couldn't quite place it. At first glance I thought it might be the broken chain link fence at the back of our academy property. But upon closer inspection I realized it was formed from some kind of netting, thick thread, or cord. My mum helped me out with a few hints and then it was easy to guess. But if you didn't live at my house, you might not be able to figure it out too well. I don't want to give it away, but check out her blog since she might give the answer in the comments soon.
PS - Just realized that my passage down below will give it away... Sorry Mum, hope that's OK.

From Glenda Quiring's blog

Brenna pushed open the front door and sighed with relief as cool air brushed against her sweaty skin. "It must be 100 degrees out there," she exclaimed as her sister, Alice, followed her into the house and closed the door behind them. "Well, not in Celsius, but probably at least that in Fahrenheit," Alice agreed. Brenna kicked off her shoes, and trudged up the stairs to her bedroom. She dropped her backpack on her bed and rummaged through her dresser, searching for something cooler to wear. Throwing on a pair of cut-offs and a tank top, she left her school clothes in a heap on the floor in front of the dresser, she sauntered back to the stairs, swung her leg over the oak banister and slid down to the main floor. In the kitchen Brenna fished around the fridge for a snack. Coming up with a ziplock of carrot sticks, she closed the bridge and then caught sight of a book on the counter. "Mum," she called, "where'd this book come from?" She picked it up and turned to the back cover. A medical book, she thought. That sounds interesting. Her mum came into the kitchen carrying a pile of tea towels to put away. "Oh, I went to the library this morning to return Mrs. Trela's books for her since she can't get out right now with her broken hip," Mrs. Morgan said, seeing Brenna holding the book. "I saw that and thought you might like it so I borrowed it for you. I hope it's good." "Wow, thanks, Mum!" Brenna grinned. "It looks great. I might just go read a little bit right now." She opened the fridge once more and extracted a water bottle, then carried it, the carrot sticks, and the book over to the sliding door. The hot air slammed into her as she left the house, but under the shade of the porch roof, it wasn't unpleasant. She walked to the end of the porch and settled into the comfy sitting-hammock. Two hours and more than half the book later, Alice opened the kitchen window to call her in for supper.