Lightweight oversized blazer

Soft white/cream oversized blazer from the Target brand, a new day . Fabric is very light and flow-y. Worn once, in like new condition. Not sure if this is a manufacturing defect, but on the collar there is a very faint blue squiggle that appears to be a string sewn inside the collar? It is not a stain and not noticeable (literally took me three years to notice it for the first time). Can take additional photos upon request.