Why does when I add my image (in high quality) to Unity icons make them blurry?

Question

Unity

So in the settings in the icons, I load my sizes of images created in adobe illustrator, then when I compile for android my icon becomes blurry, although the sources were in high quality, help me solve this problem with photos or clear instructions (NEW because), where in settings, this quality downgrade is turned off, otherwise blurring interferes with the eye