marymanard - Just takes experience to be able to tell these things. Your coin is the wrong color and the surfaces don't look anything like natural. Way too shiny.
DrDon - the reverse of that coin was struck with a very worn out die. You don't grade a coin based on the detail left by a worn out die, you grade by the detail that isn't gone. The obverse and reverse didn't wear differently, and the obverse shows EF detail. If the coin weren't polished it would be EF40.