Someone please explain this to me?

Brittany • ❤️2/23/16❤️💗Avalynn 7/26/18💕💕Ariya 5/28/19💗

So I was told my baby was a girl we’re due any time now but I’ve only been given one ultrasound and their not giving me anyone so I bought all girl clothes and everything.. but I could never understand the pictures that supposedly tell what the baby’s gender is can someone explain them to me?...