Good! Say that! Then the entire protocol and its description can be reduced to "this is a cache of ephemeral public keys and messages encrypted using them".
I know that doesn't sound quite so impressive, but that's because it isn't.
I know that doesn't sound quite so impressive, but that's because it isn't.
Additional and to some extent non-trivial difference from traditional OTR is in how these ephemeral keys are used in key exchange, whose result depends not only on DH with ephemeral keys but also on DH exchange that mixes ephemeral keys with long term ones. This causes that the ephemeral key of the passive side does not have to be signed and allows anyone to produce arbitrary session transcripts, both of these points allow significant reduction of size of the exchanged messages.
Or would have been, if they had any.