are you on a phone or ipod? If so, you simply press the attachments button in the middle at the bottom. If you are on a computer, when typing the reply, there are a lot of buttons above it for different options. Click the grey paper clip and it will open a new window that lets you browse for a file to attach, or enter the web address of a picture that is already on the internet. Im assuming you want to add a picture from your computer, so click browse, then find the picture in your files. Then click upload, and when it's done, click attach. It may take a few seconds. After it attaches, close the window that popped up, and click preview when you're done typing your response. Make sure your picture is attached, and press send.
