Images and media help explain your product and get users excited to check out your post.
Thumbnail - It is best to use an image with square dimensions. We recommend 240x240. You can use a GIF for your thumbnail, but it will need to be under 3MB. Additionally, GIFs do not autoplay so you will need to ensure that the first frame of the GIF is what you would like to appear as the thumbnail. GIFs will animate on hover.
Gallery - The recommended size for images in the gallery is 1270x760. You can upload multiple images to the gallery at once. Once the images have been uploaded, you can also drag and drop them to re-order them. The gallery will need 2+ images before it is viewable on the post page.
Video - For videos, only YouTube links are supported. We recommend uploading your YouTube video ahead of your launch and confirming that it is not set to private. This ensures it will be added correctly to the gallery. It will also need to be the full URL. Shorted links will not load. Go through this video checklist for a great starting point.
You can find additional information here: