Is that Kiernan Shipka or Christina Aguilera? That’s what the 21-year-old blonde actress had her fans asking after posing in two new Instagram selfies on June 9. In the pics, she donned an outfit that included a black sleeveless crop top and blue jeans, which was very reminiscent of the style the now 40-year-old singer wore when she was on top of the charts in the 1990s.