Advanced way is to override this file in your custom plugin.

(You can start with this skeleton plugin.)

Create a new folder 'assets' in your data directory.

Put your logo to this folder, e.g.:

assets/topbar_logo.png

Copy the mentioned file to your custom plugin and change code on:

$asset_src = elgg_get_simplecache_url('assets/topbar_logo.png');


$logo = elgg_format_element('img', [
    'src' => $asset_src,
    'alt' => elgg_get_site_entity()->getDisplayName(),
]);


echo elgg_format_element('div', [
    'class' => 'elgg-heading-site'
], elgg_view('output/url', [
    'text' => $logo,
    'href' => elgg_get_site_entity()->getURL(),
    'title' => elgg_get_site_entity()->getDisplayName(),
]));

Thanks Nikolai,

It's very hard, but i will try

I tried the advanced method, but unfortunately the logo isn't loading/showing. The browser console states

"Graphic could not be loaded."

Edge shows an image placeholder. The URL of it is

[mydomain]/cache/[anumbercode]/default/assets/topbar_logo.png

When following the link, I get the message

"Requested view is not an asset"

I invalidated the cache and clicked on "upgrade" in the admin area. SimpleCache is activated.

What could be the reason for the image to not show?

'views' => [
    'default' => [
      'assets/' => elgg_get_data_path() . 'assets/',
    ],
],

/mod/my_plugin/views/default/assets/topbar_logo.png

Awesome! It works like a charm now. Thank you for the update.

Since I already created the assets folder, I chose to add the "views" bit to my elgg-plugin.

A beautifully styled little logo can make quite the difference for the layout. :)

Added a new plugin with this feature