If not, here's how: BGG Style Guide: How to Propose Representative Images for Game Pages and Versions.
Yes, I've revived my "Not Necessarily the News" blog for the first time in six years in order to post these guidelines, and I'm sharing those guidelines here because it might be helpful for users in general, despite them not being news about games.
Note that representative images on game pages and version pages should be the 2D front cover of the oldest English-language version of the game still in print or available on the market. I know that publishers like to use 3D images in their ads, and from my understanding 3D images have a higher clickthrough rate in ads than 2D images, but BGG game pages are not ads. The image represents the game catalogued on that page, and a 2D front cover image fills the space better and is more visible at thumbnail size. If anyone plans to use a publisher image for, say, a video thumbnail or a podcast promo or a voting system at a convention, then that person will find a 2D image far more useful than a 3D one.
Publishers, give us 2D front covers or give us de... — no, wait, just the 2D front covers, please. I've been making the case for 2D front cover images since 2011, and that case still holds true. Help us help you make your game more visible and recognizable.