Based on your screenshot, your iPad is not connected to the adhoc WiFi. There should be a WiFi symbol to the right of "iPad" at the top left.
Check the iOS Settings under WiFi and ensure that it is turned on and the adhoc WiFi network name is checkmarked.
That is what I thought, but how was it able to detect that the laptop was available to serve files?
I turned on websharing on the laptop and was able to load webpages from the iPad.