The location information is provided by the internet service provider used when signing in. In some situations it may actually be the provider's location. If you are using a VPN or a hotspot, it may show a different location. If you use privacy software that hides or modifies your location information, that can affect what is shown as well.
If the time and browser shown match your own sign-in, and the location shows as Philadelphia when you sign in again, that just may be the information your service provider shows.
If you think someone else may have obtained your credentials and may be accessing your account in another location, then change your password.
