When should one make a bracha when separating "challah" from a dough? I'm assuming like almost all mitzvas it's to be done "before" the mitzvah. One has the dough prepared in front of them, they make the bracha, then remove a small piece of the dough, say "this is challah, and set it aside.
However I saw a video that shows the Belzer Rebbetzin (wife of the current Belzer Rebbe) removing a small portion of the dough in front of her, placing it into a bag, covering the dough and then holding it above the covered dough, then with great enthusiasm makes the bracha (holding the small portion) and ends off with "this is challah". Is she able to make the bracha after already separating it because she didn't pronounce that it was challah yet? I'm assuming being the wife of the Belzer Rebbe and daughter of the previous Vitzhnitzer Rebbe of Bnei Brak that she would know how to properly take challah and when to make the bracha. Is this an okay way to do this mitzvah? Is there a more preferred way (as mentioned that the bracha be made before separating anything)?