Ever had a question about Linux but felt too afraid to ask? Well now’s your chance, ask any question about Linux, no matter how noob or repeated it is, and I and others will help answer them.
Previous noob question thread: https://lemmy.ml/post/14261893
Install the package kdegraphics-thumbnailers, and then depending on the file manager you may have to enable previews, e.g. in Dolphin > Configure Dolphin > Interface > Previews.