the dimensions might be the size of the pin but the resolution isnt big enough for print.
Your screen only shows 72dpi (dots per inch)
but if your going to print something, for it to look quality, it has to be 300 dpi
if u have the large original. you can change the size in photoshop in image size. it will make the dimensions smaller tho. Hopefully when you do that it would still be big enough for the pin