I can't disagree. I think it's a case of the writing team reading the Joffrey moments and just revelling in how much of a prick he is. But, the scene DOES push the envelope - too much for my tastes as well. You've established Joffrey is both a prick AND a sadist with ordering his guard to beat Sansa (and then Tyrion's reaction/objection). I get showing a scene that illustrates that Tyrion's gift idea backfires - but it didn't need to be this brutal OR this long. Honestly, "hit her"...and maybe even "harder" and/or "with this" followed by a frightened reaction from Ros is all we needed.