"Preview screenshots" refers to images or pictures that give you a small glimpse or preview of something before you actually see or experience it. It helps you get an idea of what to expect before going further. Full definition
Players can even check out game preview screenshots to see exactly the type of gameplay to expect while playing. (pirate101.com)
Octodad: Dadliest Catch should now be available to download for the PS4, so Sony has released a batch of preview screenshots to showcase what this indie game looks like on its newest console. (entertainmentbuddha.com)
The game looks absolutely beautiful on the 3DS, the «cel shaded» look that some assumed from preview screenshots is far from the case. (nonfictiongaming.com)