The first reason why your legs look so big in pictures is because of your legs getting bigger than they really are when you are sitting down. When you sit down your thighs become bigger because they expand outwards as they go deeper into your seat. When you stand up your thighs get smaller because they’re pushed back towards your body as they extend outwards from your hip bone. This makes your thighs appear much shorter in pictures than they really are. Another reason why your legs look so big in pictures is that you’re wearing clothes that don’t help with how long they look in pictures. Wearing tight clothes can make your legs look even shorter than they actually are because they create an illusion that they’re closer together than they actually are.