While some platforms, such as Facebook pages and LinkedIn profiles, can be drafted in different languages and will be displayed depending on the user settings of the reader, other platforms only allow multilingual posts if you add several languages in one post text.
This can be an interesting way of displaying your language skills, but works better for posts that focus on the visual input, i.e. an image or a video. In this case, the decision on which language is displayed first matters – you should stick to one style, so your readers do not have to look for their language version anew each time they want to read your post. Then again, you do not want to make anyone feel second-best because their native language is not displayed first.