Yes, the problem is the image. Your image should be larger than the container of the zooming area or if the image is too small you have to use resize image on image style but still, it should be larger than the zooming area. eg, zooming area is 300x300 then image resize should be twice or thrice larger such as 900x900 but the image will result as pixelated. Please forgive my english and grammar for as I am not fluent in English. I'm just trying to explain :)