This is the grid gallery post.
It can be added by going to Gallery → Add New and uploading the image to the post. Available Gallery Posts templates:
- Single Image – with / without the lightbox
- Grid Gallery – Grid/Masonry – the option can be set in the theme panel
- Slideshow – images are presented in the carousel slider
- Video Post – local & 3rd party videos can be added from websites such as YouTube, Vimeo, DailyMotion etc
- Audio Post