The position is from today's game in the Women's World Championship, Anna Zatonskih vs. Marie Sebag, courtesy of chessbomb.  (The engine at chessbomb somehow missed Anna's move.) White is threating to mate via Qh6, so the power of Re7 is that it forces black to give up the queen.  Rxe7 loses on the spot.  

nice one.

Didn't get it on a spot, thought that Qh6 is winning. Later on I saw that black queen can retreat to f8, so this move is really fantastic.