Reveal element on scroll

Hello everybody,

I’m a graphic designer trying to make my new site on Webflow.
I’m spending hours learning this great tool !
But i’m stuck in the home page trying to make my works reveal on scrolldown. Everything is going fine exept that when my images appear, there is the default image background behind them that appear too.

Can u see what i mean ? And don’t know how to remove it…

Anyone could help me ?

Thank you so much.

Here is my public share link: LINK
(how to access public share link)