During the conversation between (approximately) 0:20 and 0:29, there are many shot reverse shot used, which also happens throughout the clip. The shots are mostly used to show the little, frightened girl (Max) reacting to the strange demands of her new adoptive older sister (Esther) - Esther wants her to stop a car by waving her hands. This increases the relationship between the character and the audience because we feel very sorry for the little girl; she can't fully understand the situation, as she is young and deaf. Furthermore, because Max is young, she is naive and trusts Esther. The audience can infer that Esther is not a normal child, and therefore feel very sympathetic towards Max. This is conventional for a thriller because the audience must be aware of the good/bad characters, sympathising and empathising with the good characters.
From 0:22 - 0:29, there is a 'linking of shots' editing technique used. Shots of the conversation between Esther and Max are interspersed with shots of a single car driving along the road. Since Esther is telling Max to jump in front of a car and wave her arms to stop it, the audience knows that this is the car she means. The shots are linked together to add emotional impact, and warn the audience of what is approaching: Max being pushed in front of the car. This creates a tense atmosphere as the audience is on edge about forthcoming events, and causes them to worry about the little girl. This editing technique is an effective and conventional way for thrillers to engage the audience with the film, and make them feel the character's fear.
From 1:13, fast editing is used to show Esther beat the nun and throw the hammer away. The fast editing adds excitement to the scene, and also enhances the shock of the unexpected violence. This scares the audience, and they also sympathize with the nun who is getting beaten. It's conventional for a thriller (and other genres) to use fast editing when there is action or violence. It enhances the viewer/character relationship when the audience is paying more attention to what is happening on screen; the audience watch more closely when fast editing is used so as to see all of the different shots and events.
At 2:28, there is a jump cut to the hammer that Esther is using to kill the nun. The camera suddenly focuses on the hammer immediately before the final hit is shown, to enhance the feel of shock and surprise for the audience. It also increases the importance of the weapon. Thrillers always aim to shock the viewer, which can be achieved in many different ways; jump cuts are just on. Moreover, we can see that the hammer is very high in the air and will come crashing down on the victim. This makes the audience uneasy, and also feel sympathetic towards the victim. This again is typical of a thriller film, as it is important for the audience to connect with the characters and the storyline for the full psychological effect of a thriller.
In summary, editing styles are used within this clip and the thriller genre to create tension, shock or surprise. This is also effective in engaging the audience. In my own thriller, I aim to create the same atmosphere using similar editing techniques.