To attach a file to a bubble,
Attached images will be automatically displayed inside a bubble.
the image to display buttons to
If the uploaded file is not an image, a link to the file will be displayed in the bubble.
Once a file is uploaded, you can open it in the following ways:
If the file is an image, a thumbnail of that image will be displayed inside the bubble.
If the file is not an image, it will be displayed as a link. Clicking on that link will open the file in a new window or download the file. This download or open behavior is configured in the browser settings.