Hi Patrik, there are a couple ways of doing this without having to edit the theme php script files involving CSS only solutions. Which will work for you will depend on the image you are wanting to use and its size.
This solution adds the image as “content” to the front of the site title div (#masthead h1). It doesn’t allow much control of size, so the image would need to be sized properly before you add it.
#masthead h1:before {
content: url("URL_OF_IMAGE");
}
This second solution adds the image as a background to the site title div (#masthead h1) and then adds padding on the left of the site title to make room for the image. This allows a bit more control over things. I’ve used the background-size declaration and contained the image to the space available (in this case the height).
#masthead h1 {
background: url("URL_OF_IMAGE") no-repeat scroll 0 0 transparent;
background-size: contain;
padding-left: 40px;
}
In both cases you would replace URL_OF_IMAGE between the quote marks with the URL of your uploaded image. I would suggest sizing the image as close to the final size you wish to be displayed so that it stays as sharp, clear and crisp as possible.
If after trying the above two solutions, if you cannot get things right, let me know and please provide a link to the image in your media library for my reference.