@Kaleb Do you mean like a thumbnail of a Steam Workshop item? It is created automatically when you upload a map to the Workshop, but it's bugged and doesn't work on the 64-bit version of the game. You need to right-click on Company of Heroes 2 in your Steam library, go to the Properties menu, then navigate to the Betas tab and choose the 32-bit version. After that, open the game, upload your map to the Workshop, and then you can switch back to the 64-bit version. :)

If you're asking how to get an image of your "minimap," this image file is also created automatically and is located in the same folder as your map (scenario). The file has a .tga extension, which you can open and export as a .png or .jpg using Photoshop or GIMP.

question how did you get your image of your map on the front liek the main image?