The "better" photo of the button is still out-of-focus... and, dark. I can't tell what is above the shield (perhaps a droop-winged eagle), nor tell what the two objects inside the shield are.
All I can tell you with certainty at the moment is that your button doesn't seem to be shown among the various State Seal buttons in the Alphaeus Albert book. So, I think it is most likely a City Seal or City Police button. It "resembles" some New York city buttons. Those show a droop-winged eagle standing on a globe (or half-globe) above a spade-shaped shield, with a person standing beside the shield on each of its sides.
You said your button's back says "Philadelphia." The most common button-backmark saying "Philadelphia" (fully spelled out -- not abreviated Phil, Phila, or Philada) is a Horstmann Philadelphia backmark, which dates from 1893 to 1947.