Demi Lovato is sporting a new and shorter look this summer.

The 21-year-old "Heart Attack" singer tweeted a picture of her new bob hairstyle, along with the caption, "Just went shorter!!!" - adding some colorful emoticons to the post. In the picture Lovato is seen sitting in a hair salon chair, while a worker styles her hair.

Hairdresser Riawna Capri, co-owner of Nine Zero One Salon, told E! Online that the haircut was a "spontaneous decision" and that the former "X Factor" judge was inspired by singer and dancer Julianne Hough.

"It was definitely not planned," Capri told E! Online exclusively. "[Demi's] flying out today, and wanted it before she left. Demi loved the texture of Julianne Hough's old haircut. She wanted to recreate that texture on her. Demi and I collaborated together about the cut. I wanted to give her something no one else has."

Capri added: "It's short on one side, and longer on the other side. One side is about 3 inches longer than the other side. The short side touches her shoulder, and the long side goes just past her shoulders. It's that perfectly disheveled hair."

The "Neon Lights" singer is known for regularly changing her hairstyle - going from her natural brunette roots to platinum blonde, bright pink, blue and more recently sporting silver and purple ends. Earlier this year, the singer shaved the side of her head.

"I was painting a picture. I've done so many 'Julianne' haircuts, so to recreate that texture, I feel like I can do it in my sleep," Capri continued. "She was so pumped, she loved it."

What do you think of Lovato's new hairstyle?