Welcome to the challenges, Aiché! These weekly activities are a fantastic way to learn and practice Storyline.
Cool idea using the Instagram interface. The grid-based layout makes it an easy visual to use for photo collages. it's also a perfect way to practice using triggers and slide layers.
I noticed you posted your example to Tempshare. Tempshare's a great solution for testing projects, but it will automatically delete files after 10 days. Would you mind sending me your published files so I can upload them to our server? Another option is post the files in the forums so others can view your work, offer feedback, and allow me to grab the files. Whatever's easier for you.
Thanks again for sharing your work this week! Hope to see you around more challenges!