My guess is that the pic is some instant translation app that tries to mimic the original font. The Google translate app has this feature where it replaced text with a translation in real time through the camera.

You can use tools like whishper to pre generate the subtitles. You will have pretty accurate su titles at the right times. Then you can edit the errors and maybe adjust the timings.

But I guess this workflow will work with VLC in the future as well