This is part of our #women140 series that looks at top women on Twitter. Read the full report here. Ashley Mayer is the director of communication at Box Inc., one of the valley's fastest-growing companies (valued about more than $1.2 billion and eyeing a 2014 IPO). Her Twitter bio? "Too weird for normal twitter, too normal for weird twitter." Here she describes why she was late to the Twitter game, her strong "impulse to share," and how she learned that her dog is incredibly photogenic. Follow…