the low shot is used to make the robot seem tall.
The way the robot towers over the picture,gives the effect to the audience that the robot is large and physically dominant.
In the picture to the right taken from the film Inglorious Bastards, the low angle used makes the two figures seem dominant and threatening as they're looking down at the audience. The low shot is used a lot in Tarintino movies, a very popular low angle, which is frequently used in Tarintino movies is the famous 'car boot' shot. Its a low angle shot which is from perspective of a car boot. Tarintino has used this in a different way, instead of using it to make a character look powerful or dominant, he has used it to add mystery to the scene to get the audience questioning what the characters are looking at.