This is one I can answer! That square usually contains a link to another King game, but on the latest live build it seems it has mysteriously disappeared. The team is aware though, and are working on it 😄
Hi @undercon2 Yes I am seeing the blank square as well. When it first appeared yesterday it asked me if I wanted to play the Candy Collection event to win a lollipop. I collected one hundred green candy to win the lollipop, but the square has been empty since then.