Why the difference?

[congratsx]

fn render_posts(posts: &Vec<PostCmp>) -> Element<Message> {
// let c = Column::new();
// let posts: Element<Message> = posts
// .iter()
// .fold(Column::new().spacing(10), |col, p| col.push(p.view_in_list()),
// )
// .into();
// c.push(Text::new(String::from("Posts:")).size(15))
// .push(posts).into()
column(
posts
.iter()
.map(|post| {
post.view_in_list()
})
.collect(),
).into()
}

I am new to rust and iced, why do commented codes not show up and uncommented codes show up normally. Why does this happen, this is full code

Thanks