Take this media entry:
As you can see, I added it as a transcript.
And take this citation:
I have added the transcript in both places.
The source should show the document you consulted in the form (original or image or PDF) available to you. If the media was only available as a transcript, or index, or offline original, your citation should say so.
However you consulted the source, you should include your transcript (as this is the record of what you think the source said. Others might think differently, if the media is hard to read, for example; or they might not be able to consult the source you used; or the source might become unavailable online if the agreement between the person (etc.) who hold the rights to publish and the current publisher (currently, Ancestry) expires, and you can no longer view the media. (it has happened more often than you might care to think).