Diana had opened her mouth to clarify that the girl in the photo wasn't her cousin- it was just another girl named Diana- but Cadence's terrible mood made Diana reconsider and shut her mouth. She was bummed that her friend left as well when Cadence stormed out. Now she was the only short one again.

Moving on from the topic of, well, herself, Diana took a sip of her coke then joked, "When I ordered coke, I was expecting it to be more powdery than this." A dumb grin was plastered across her face as she said that. 

It was odd seeing a childhood friend again while pretending to be a different person. She knew who Cadence was but she didn't know who she was. Diana couldn't help but feel a tad guilty for at least temporarily ruining whatever was going on between Derek and Cadence.