Currently EzyCourse suggests to use 740x380 size for course (cover) images, which is equal to 16:8.2. While the featured image for the blog is defaulted to 16:6.8. These are not common image ratios. YouTube, Vimeo, Udemy, Skillshare, etc. all use 16:9 ratio for their thumbnails. Since most of the course content is video, EzyCourse should accommodate the website layout and suggest users to use 16:9 as the default ratio. I know that EzyCourse accepts different kind of image ratios, and just crop (object fit "cover" in CSS) to fill the container. But in order for the authors to have the image not cropped, they have to create designs in 3 sizes. One for the video thumbnail (used by the Bunny.net video host) in 16:9 ratio. One for the course cover in EzyCourse in 16:8.2 ratio. And one for the blog in 16:6.8, if the author wants to announce the course on his blog. I think the current default image ratios are just a headache for many authors as they have to create different image sizes.