Tell/Ask HN: My Location is different on iPod touch vs Laptop Google Map

I used the "Show my Location" feature to find out my current location using my laptop and my iPOD touch device's built in Maps. Apparently, the iPOD touch is showing that I am about 1 mile away. (It used to show the accurate location before)

I am using the same WiFi network for both(my home Comcast cable) and they are in the same internal private subnet effectively having the same public facing IP. I am curious how this is possible as I thought the IP is resolved to the location.