This is retarded bait, but I'll take it.
1) It's not a "free speech site" and Null doesn't claim it is. It's a forum with a purpose and a culture, and if you shit the place up you get banned. You don't get banned for your politics or controversial opinions, which somehow became radical in Current Year; but that's not a license to be a disruptive, off-topic, shit-flinging retard.
2) Images aren't speech. Speech is verbal, as in having to do with words, either spoken or written. Images are visual. Both might convey some idea, or both might not. Words are explicit while images are suggestive; conversely, images are more efficient at being physically descriptive, while words are more efficient at conveying non-physical things. The parts of your brain used to process the two are different, your response to the same "message" is different between the two mediums.
Now, images can be artistic expression, but that's still different from speech. You could argue that freedom of expression falls under freedom of speech, but in reality it's the other way around: speech is a subset of expression. There are many different ways to express oneself other than speech, and there are many more ways to convey ideas and meaning other than words.
So even if someone declares themselves in favor of unlimited free speech, they aren't expressing support for unlimited free expression. You have to make a specific claim up the logical chain to get there; it's not automatically downstream of that belief.
(This gets muddied sometimes in the US/EU by laws around speech, because of the way the legal systems are set up. To summarize a long legal analysis, documents like the Constitution and 1st Amendment left a lot of rights unlisted, implicitly protected, or explicitly delegated to the people, on the assumption that the country would protect them as a matter of tradition instead of a matter of law. But courts and laws naturally gravitate to explicit text and protection, which is why a lot of freedom of expression cases got lumped under "freedom of speech" protections over the last 300 years.)
