Install apt-config-icons-hidpi by entering the following commands in the terminal:
sudo apt update sudo apt install apt-config-icons-hidpi
APT configuration snippet to enable HiDPI icon downloads
This package contains an APT configuration snippet that enables the download of an icon tarball containing application icons for display in software centers. Icons get downloaded directly from the archive via regular cache updates, and match the software currently available in the respective archive suites. . This snippet enables icons in the size of 64x64@2, that are suitable for HiDPI displays.