Joomla, Yootheme Pro, Tutorials, Translations

Create 1 'Builder' or simple html module for each language. Name them accordingly and set the language for each one of them.

Each module should be set to "Logo" position to appear on the medium screen sizes and bigger screens.  In order to show them also for mobile, repeat the process placing the modules on "Logo mobile" position.

On this site I have 3 languages: English (UK), English (US) and Spanish.  I have English US as the default language of my content.

As for the modules, both are identical except for the language and the image they are showing.

Remove the logo of your site found at Yootheme Pro Builder -> Layout -> Site

That's it! it's the simplest way.

Things to take under consideration

You can use an html module or a Builder module if you want to make more complex configurations like showing a module inside a module or showing more than just a logo, for example but I'm keeping it simple here.

I had to install English (US) and set the default language to US English because I was having duplicate logos in Spanish (one in English, one in Spanish) 

There's another way that gives you more control over these variables but I'll show them in a new Yootheme Lab.