For organizations with strict language requirements, there is often a need to be able to present content in multiple languages. For example, a user must be able to view content in language "A" on one browser tab, and view the same content in language "B' in a different browser tab. This bulk of this requirement can be achieved by producing a different view for each language, and providing the unique URL for each view. However, there is currently no way to set the language of the toolbar in a view, as the toolbar language in a view is currently set based on the user's language preference in their account settings.
There is currently no way to programatically change the user's language preference, but even if there was, this would not work for "Guest" users. Additionally, this would not meet the requirement of having two tabs open simultaneous with different languages.
The easiest way to address this problem would be to expose an embed/URL parameter that sets the toolbar language, which would override the user's language preference.