>>/28196/
Because it gives 18 BMI as a result (exactly 18.0, what a coincidence). Instead with 5'2 or 5'3 and 108lbs you'd get 19.1-19.8, which is normalweight, but egirls like her are lobotomized by pedophiles and anime into thinking that it is "aesthetic" to be underweight and that 18 or lower are the ideal BMIs.