that looks like photon, which lemdro.id is using as default interface.
there has been a feature request to add language selection to it, but it doesn’t seem to have been picked up yet: https://github.com/Xyphyn/photon/issues/182
unfortunately lemmy still doesn’t provide a great user experience today for posting content in other languages. many users don’t realize that they should be setting the languages they want to see in their profile, so your audience with a properly language-tagged post will probably be substantially smaller than the number of people who could understand your post. additionally, many third party apps/interfaces and even the official mobile app don’t support language selection yet when posting.
i recommend using https://l.lemdro.id/ for posting with the appropriate language tag, which is the official standard lemmy web interface. for comments it doesn’t matter that much imo.
you may have been thinking of https://poliverso.org/objects/0477a01e-1166-c773-5a67-70e129601762, which was neither lemmy devs, mastodon devs nor lemmy.world admins