This is a vintage women's white top from Portraits By Northern Isles in size 8.
It measures about 20.75" underarm to underarm, 28.25" from the back of the neck to the bottom hemline, 21" across the waist, 16.25" shoulder to shoulder, 23.75" shoulder to hem, 8" waist to hem, and 21.5" shoulder to sleeve opening when laid flat.
The garment comes in good pre-owned condition.