Open Instagram and swipe right to open the Story camera
Tap the gallery icon to choose a photo
Add the first picture to your story
Tap the sticker icon
Select the photo sticker
Choose another picture from your gallery
Resize and move the new picture on the story
Repeat the photo sticker step to add more pictures
Use the layout tool to place multiple pictures in a grid
Use copy and paste if you want to duplicate images
Tap Your Story to post it