It does not help
I realized what the problem
The problem is that the applet "Show Desktop" uses image format SVG. On the other icon theme this problem is not observed, so the problem is in icons Mint-X, which has some of the images in a format SVG.
The path to the image, which uses an applet:
You just need to open the image in GIMP and save it in the format of PNG.
Image should be saved as "user-desktop.png", and the old image, "user-desktop.svg", which stretches to remove.
Do not forget to link to the image of "user-desktop.png", with the name "desktop.png".
After the link with the name "desktop.png" has been created, you can delete the old link "desktop.svg".