Hello! I have managed to find a reason that cause that problem. It can be easily reproduced with Polymer logo, for example:

The problem occurs only with images with transparent background. So my guess is that emoji-llate component has two hidden canvas tags that you are using for conversion. Then _getPixellatedImageData receives not clean data but some merged result from these 2 canvases that affect each other.
I hope it will help to fix the problem!
Hello! I have managed to find a reason that cause that problem. It can be easily reproduced with Polymer logo, for example:
The problem occurs only with images with transparent background. So my guess is that
emoji-llatecomponent has two hiddencanvastags that you are using for conversion. Then_getPixellatedImageDatareceives not clean data but some merged result from these 2 canvases that affect each other.I hope it will help to fix the problem!