I don't know to be honest. I know Ben is pissed because Locke could see/hear him. That was a pretty strange scene. On another web site, some guy slowed down the video and got a screen capture of Jacob's face.
From Lostpedia:
http://www.lostpedia.com/wiki/Jacob
When Locke attempts to leave he hears the words "Help me." The voice is low and does not sound like Ben's. Locke turns back around and asks Ben what he said. Ben says he said nothing, Locke turns on the flashlight and starts to tell Ben what he heard. Just before Locke repeats Jacob's message items in the room seem to shake on their own, some items seemingly thrown. This keeps Locke from relaying Jacob's secret message to Ben. Ben attempts to stop Jacob, but he is forcibly thrown against a wall. In the midst of this a brief image of a man, Jacob, can be seen.
From Lostpedia:
http://www.lostpedia.com/wiki/Jacob
When Locke attempts to leave he hears the words "Help me." The voice is low and does not sound like Ben's. Locke turns back around and asks Ben what he said. Ben says he said nothing, Locke turns on the flashlight and starts to tell Ben what he heard. Just before Locke repeats Jacob's message items in the room seem to shake on their own, some items seemingly thrown. This keeps Locke from relaying Jacob's secret message to Ben. Ben attempts to stop Jacob, but he is forcibly thrown against a wall. In the midst of this a brief image of a man, Jacob, can be seen.