To change the number of photos in a multi-image or multi-text carousel:
  1. Navigate to onMessage
  2. Website
  3. Site Name
  4. Styles
  5. Click Edit on the style you want to update the number of text/image items for.
  6. In the left column click the gear icon, then click the Edit Settings button. 
  7. Scroll down and you should see boxes for minimum and maximum number of items, you can change these here.

The minimum setting will allow the content block to shrink down to display at least that number, ensuring the set slide width is honored, and otherwise scaling the items to fit.

The maximum setting will allow the block to grow when the style is applied, displaying a maximum of whatever number is set for max, using the minimum slide width or greater to scale items up to fit.