How can I add a photo to my email signature?

Yes it is possible. See the example below. You can have any photo including an animated gif that is already on the web. Place the picture on the web. That may be a problem since many photo sites are blocking any copy of an image. It will not work with Flickr. The best place is your own private website. There is no way to have an inline image directly from your computer in Yahoo mail on the web. It requires a separate email program. Go to the picture on a website and right click on it and copy or copy image, depending on your browser. Now go to the email body or signature and paste it. The picture should appear. If not then there is a problem. The picture must remain on the web since an html link is used to access the picture every time the email is viewed. ℬ ℋ https://s.yimg.com/hd/answers/i/8603ca4636f04604a4dbec4e23ba964d_A.jpeg?a=answers&mr=0&x=1400191321&s=e187869fe0d310b92d4b007bb87ff546

What email product or site do you use?