You'll give some more information about your project.
How are you determining slow vs fast? Do you have fps numbers?
Do you have a lot of sprites layered over each other? Transparent spirits cost a significant amount of resources as well.
Are you running any loops? That is another common source of slowdown.
Also the pixi looks like it's a three year old budget smart phone running a severely out of date version of android which may not even support webgl. Remember that your computer is generally going to be significantly faster than any high end smart phone, so a low end one may not be able to provide a satisfactory result.