How to add an image as a bullet point in a specific WordPress widget? [closed]

You can do this by modifying your theme’s CSS, which you can get access at Appearance > Editor in the Dashboard.

You will need to style the widget list element by dropping this in your theme’s style.css

.widget.latest-tweets .widget-wrap ul {
    list-style: none;
    list-style-image: url(http://your-image-url-here);
}