Size of Virtual Machine Windows 7 smaller in MacOS finder

I have a virtual machine with Windows 7 where there is 20GB from 90 GB available. In the finder of MacOS the file is only 59 GB. Is this possible?
(Parallels Desktop Pro 14 under Mojave)

 

Parallels virtual machine takes as much disk space as you have data in your virtual machine, and it's all stored in the virtual machine's *.pvm bundle (by default in ~/Documents/Parallels/ folder).
But for more info, could you please share screenshots of disk size in VM and .pvm bundle size?