If like me, you've updated to the latest version of Android Wear on your smart watch, you may now be seeing the "OK, Google" text awkwardly placed over your watch face as in the below picture:
As it turns out, this is part of a tutorial meant to make you aware of the voice commands; unfortunately there is just no indication of that.
If you want to remove this text, you simply have to use the voice command a few times. It disappeared for me after using it seven times, the last few times of which I just brought up the menu by saying "OK, Google" and no subsequent command.
And voila, I no longer have the annoying text!
Not all Android Wear users seem to be experiencing this, so presumably it's only affecting users that haven't used the voice commands much.