This sample demonstrates the custom thumbnail of the File Manager you can customize with your own icon using showThumbnail property.
The File Manager component is used to explore a file system through a web application, similar to the windows explorer for windows. It supports all the basic file operations such as create, rename, delete and so on.
Note: File Manager's upload functionality is restricted in the online demo. If you need to test upload functionality, please install Syncfusion Essential Studio on your machine and run the demo.