Nudges are a way to connect with people without going live.
You can use Hello Tiger and see selfies that other people have took, if you like what you see, tap Nudge. If the other user has app notifications turned on, they will get an alert that you have nudged them. They can then chose to add you to favourites (the nudge icon will be displayed next to their name so you know you have connected via nudges as opposed to live chat), ignore your nudge, or block nudges from you.