You can add images to the comments field in three ways:
1) Click the image icon to select a file to upload.
2) Drag and drop the image from your computer into the comment area. Hold the Shift key to bring up the optional image cropper.
3) Copy/paste the image from your clipboard (NOTE: Copy/paste is currently only supported in Chrome. It will be added to other browsers when it becomes available in the spec).
Animated GIFs will become static GIFS when copy pasted.