The pre in preview means that the students were able to see the movie before it actually came out.
To most of my research so far, it is the visual of speech sounds. When you look through a dictionary, you'll usually see these things under the main word you're looking for.
For example, you take a word like "Seahorse". You have the word type, and below the word type, you see some fancy looking text.
I will bold this mini dictionary bit for you to show you what we're focusing on.
Seahorse
Noun
/ˈsēhôrs/
The text in bold here is what you're looking for when you want to find the "Phonetic Transcription." Hope this helps!
