Elfs ?

Ladies excuse my dumbness my family never have done anything like that for Christmas ever since LO we celebrate Christmas <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> and Christmas Day on <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> we have Get dolled up and have dinner together and just enjoy each other, on Christmas Day we open presents and play games and eat left overs and make something else for dinner all at grandmas house,when she passed was then at my parents house. Lately on FB I’ve seen post of pictures of Elfs and ideas. This is a screenshot. Can someone explain what this is?? I tried reading the comments and seems like everyone knows what this is lol except me I have a 11 month old and idk if this is something cute or what? How does it work? What is it? Just takes photosoot of elfs and do what? Lol?😂