I’m on QQ, Chinese social media and messenger, and wanted a different emoji that I could not find. Here’s how I added one.
You’ll need to edit your original graphic. The file format size is 32×32. Save your file in .png so you can have a transparent background. You can reduce the size of the image of your choice, but the simpler the better, as at 32 x 32 px almost all details will be lost. I have sized existing QQ emojis and they are 28x28px or smaller. This is a more appropriate size.