I read the guide below and tried,
but when I upload a file to my page and click the thumbnail, there's no reaction from the thumbnail.
How can I resize the thumbnail of uploaded file or switch it to a link????
Insert a file into your page
There's a few ways to insert a file into your page:
- Go to Insert > Files on the editor toolbar and select any of the previously uploaded files, or
- Drag the file directly into the editor (this will upload and insert the file in one step), or
- Type ! and choose an attached file from the autocomplete drop down.
Your file will appear on your page as a thumbnail. Click the thumbnail to resize it or to switch to showing the file as a link.
https://confluence.atlassian.com/doc/display-files-and-images-245827130.html