Joffrey is mostly M.I.A. throughout "The Climb," until the episode's closing minutes. Thankfully, he doesn't speak, sparing viewers his sniveling voice. Not so positive, though, is the manner in which we see Joffrey.
In his bedroom, armed with a bow-and-arrow, he's just finished firing arrows into head whore Roz, who's been tied to his bed's frame like a sacrificial, naked lamb. Joffrey's target practice is Roz's gruesome, barbaric demise. Six arrows have pierced her body, including one to the heart. Blood drips down her face, sliding over the mouth that sealed her fate. She's become Joffrey's latest murder victim because she ratted on Littlefinger, telling Varys that Littlefinger plans to take Sansa away from King's Landing.
Killing Roz doesn't do much for Joffrey's power status, but it does confirm something that could ultimately be more intimidating than his dominant authority: King Joffrey is a budding, sadistic sociopath. Margaery, Sansa, and, hell, even Mama Cersei better watch what they say and do.