it does this by making your tor traffic look innocuous and random

As mentioned in the quote above, pluggable transports help to fool your ISP, the Great Firewall, and other kinds of censors. It does this by making your TOR traffic look innocuous and random. At the moment, the most popular type of pluggable transports is called Obfuscated Bridges, which run one of the following two protocols:

1. obfs2
2. obfs3

Obfs2 (The Twobfuscator) is described in detail on the following official page:

https://gitweb.torproject.org/pluggable-transports/obfsproxy.git/blob/HEAD:/doc/obfs2/obfs2-protocol-spec.txt

Essentially, obfs defeats DPI by making your network traffic look like random data packets instead of TOR. However, you should know that, should a hacker be able to “sniff” your network connection while you first connect to the Obfuscated Bridge, there is a chance that cryptographic data can be stolen in this way. The actual contents of the data you send and receive will still be protected by the TOR protocol, but it will once again be possible to discover that you are using TOR. Such an attack, requiring some skill and resources, is not the most likely threat, but the security mindset demands that you are at least aware of the possibility.

To learn more about Obfs3 (The Threebfuscator), have a look at:

https://gitweb.torproject.org/pluggable-transports/obfsproxy.git/blob/HEAD:/doc/obfs3/obfs3-protocol-spec.txt

Obfs3 is technically quite similar to obfs2, with the main difference being that the initial handshake between your computer and the Obfuscated Bridge is more secure than obfs2 (a customized Diffie-Hellman key exchange, in case you like big words).