It's great that you're curious about these changes! Let's break it down step by step:

1. Understanding Prepubertal Girls: Before puberty, girls are typically around 8 years old and younger, and their bodies are still developing. They don't have the same physical changes that happen during puberty, which is why it might feel less serious or embarrassing for them to be seen without clothes. At this age, children are often more innocent and are still learning about their bodies and privacy.

2. What is Puberty? Puberty is a time when children's bodies start to change as they grow up. For girls, this usually happens between the ages of 9 and 14. During puberty, girls start to develop breasts, and their bodies change in other ways too. These changes can make them feel more sensitive about their bodies and their privacy.

3. Understanding Privacy: As girls go through puberty, they often start to care more about how they look and how others see them. This means they might want to have more privacy when they are changing clothes or showing their bodies. It's normal for people to seek privacy as they grow older and become more aware of themselves and others.

4. Feeling Comfortable: Everyone has different comfort levels when it comes to their bodies. After puberty, many girls feel like they need a private space, like a dressing room, to change clothes. This is an important part of growing up and learning to respect both their own and others' privacy.

5. Social Rules: As kids grow into teenagers, they also learn social norms and rules about what’s considered appropriate behavior. Being more private with their bodies becomes a part of those norms. They may feel embarrassed or not want to show their bodies in public because of these new understandings.

In summary, it's about the changes in their bodies, feelings about privacy, and social norms. All these factors help explain why girls might feel differently about showing their bodies before and after puberty.