Media Gallery widget is a tool to display photo in 2 formats (Carousel and Grid). 

1. Click on Layout button on the top right side of the page
2. Click on Create New Widget button and select Media Gallery widget
3. Enter widget description and widget title if you want to show title of the widget
   
4. Select Gallery format (Carousel or Grid) 
5. Upload image from [Choose File], then enter name and alternative text for the image. Optionally enter an Image Caption (this will be shown below the thumbnail if you select Grid format)
6. Click Create media item to finish adding the image.
7. Click Add new media item button near the bottom of the form if you want to add another image
8. Save the widget
9. Drag and drop the newly created widget from widget list into page layout
10. Save layout

Sample of Media Gallery Widget