It would be extremely helpful if a preview of cloud files (especially for images) can be provided similarly to how dropbox functions. Is that something on the roadmap? Thank you!
This is not something that is currently on the roadmap.
You can use the right-click->“Open Web Preview” option to browse the images and determine what you want to download that way. It is not as convenient as direct thumbnails in Finder/Explorer, but it can come in quite handy.