Why do language tags appear near the user´s name on split rooms?

Near some user´s names, when split rooms functionality is used, language tags might appear as below:

When the split rooms functionality is used on a non-translated session, the tags might appear only for users that were created in the past when a personalised language was available to be set for the user.

For newly created users, the language tag is appearing only when using the split rooms functionality with a multi-language/translated session taking into account the language selected by each user.