#2- Total Submission
Once your dog gets this position, then they are all yours. They have surrendered to you. In this case you are more than welcome to pet them, massage them, and even play with them as you want. 
#3- Fearful and Worried
Your dog might be scared of something or someone. So please make sure to make your dog feel secure, and comfortable, in order to prevent any unpleasant event. 