On my Windows system, if you click on the paper clip in the above box, it will enable you to attach a file (or picture) to your post. You only need to know where the picture is on your computer and the file name. I think you can also click on the yellow box that looks like it has mountains in the background. I don't know that the difference is, but I think either will work. I don't know anything about Apple computers, but try it to see if it works.