It is the Mint boot loader not Windows i.e. you are useing the Mint boot manager to control your dual boot... this happened because you installed Windows first then Mint and that makes Windows use the sub-standard boot screen that came with Mint.
As you say, its a minor issue so put up with it or remove the Mint install and repair the Windows boot with a auto-repair from a Windows 8 or 8.1 disc | usb.