The first photo are 3-6mo and 6-12mo (80&90) side by side. The second photo is 80 stacked on top of 90. As far as I can tell, they are the same size, or have the slightest differences. They were different prices when I purchased, so I’ll be keeping the cheaper and returning the other.The quality is as expected, and the fit of both are similar to Carters 6mo sizing. Our daughter is wearing this for a spring photo sitting, as I learned for our last sitting that skirt/dresses aren’t the most photogSee full review