You have received notification that you have a connection request that will need to be accepted.
To find the request select "More"
Then select "requests" from the top Menu bar:
Find the other Shuffle User that you would like to connect with and select the "Orange Icon" to approve or decline the connection:
Select which action you would like to take:
You then have the option to start a Chatter or not.
Once connected, you will see the other Shuffle User in your "Contacts". Make sure to request cards or start Chatter with the User that has an "Shuffle Icon" next to their name: