Key to my heart flowy white and black dress

This is a size medium key to my heart dress which would fit a size 4-6. It has a stretchy waist line and fits loosely everywhere. The sleeves are very oversized as well. It has been warn and washed once. There is a faint yellow Lon at the very top of the dress which I’m not sure what that is from. It is pictured as well. Any questions please ask.