I found the steps involved in creating a representation to be a bit unclear.

3. Let representation be a new representation.
4. If representation’s MIME type essence is "text/plain", then:

How can it be "text/plain"? Shouldn't we check the essence of mimeType, which is:

1. Let mimeType be the result of running the well-known mime type from os specific format algorithm given systemClipboardRepresentation’s name.

Lastly what should we actually do with data from clipboard? Spec is not clear about it, currently Servo implementation resolve representation's data with it.