Extras are also known as background actors. You are meant to be in the background. Think of an extra as furniture, moveable furniture helping to set the scene. Also, if you stand out as an extra, the chances of booking a speaking role on the same show later on will be zero.
Can I wear jeans to an audition?
You don’t need to dress like you’re going in for a corporate interview here. Your clothes shouldn’t be a wrinkled mess, but you also shouldn’t be wearing business attire to an audition. A good pair of jeans can go a long way, and it’s worth investing in a pair for auditions alone.