Why there is a grounding on device with two prong cord?
Unless your house has an old style unearthed socket (CEE 7-1), the more modern schuko sockets (CEE 7-3) have two earth tabs - little metal wipers top and bottom that contact the earth connections on the cable. These are found in the majority of EU countries (notable exceptions include the UK and France).

There is also a second style of socket (CEE 7-5) that has a earth pin that engages with the hole in the plug. These are typically found in France.

If your sockets don't have the wipers, or the earth pin, then the issue is with the sockets not being earthed, not the cable which is wired with a hybrid (CEE 7-7) earthed plug compatible with both styles of socket.