If you have saved it to your device, you can press the pictre icon that comes up when you post/comment/answer, next to the flag and the little grid. Click the upload tab, click choose file, it should show your files if you are on computer, or it will give you a few options if you are on something like a tablet, click files. Then click on the gacha image. Now click send it to the server. Now click ok. You should see the image in the answer/comment/post. Now just post it.
