Windows shortcut arrow icon, it's used to distinguish normal files, but for aesthetic reasons, we all choose to remove.

Windows imageres.dll,197 is a transparent icon in the system icon resource.
Reg HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Icons can control shortcut icons.

Remove

reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Icons" /v 29 /d "%systemroot%\system32\imageres.dll,197" /t reg_sz /f
taskkill /f /im explorer.exe
attrib -s -r -h "%userprofile%\AppData\Local\iconcache.db"
del "%userprofile%\AppData\Local\iconcache.db" /f /q
start explorer
pause

Recovery

reg delete "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Icons" /v 29 /f
taskkill /f /im explorer.exe
attrib -s -r -h "%userprofile%\AppData\Local\iconcache.db"
del "%userprofile%\AppData\Local\iconcache.db" /f /q
start explorer
pause