The wording "you might feel aroused anyway" suggests no such thing.
I noticed this too, but in context I don't think it's the most natural reading. It seems as if the audience is assumed by default to be composed of heterosexual males, with the word might acknowledging that they might or might not be aroused by this particular picture at this particular time. See notes to slide twenty-nine: "You stealth-compute 'sexiness' as a property of Jessica alba by unconsciously evaluating signs of her health and fertility in her appearance."
It's also untrue: the pixels on the screen are real,
Here I'm inclined to defend the original phrasing. Criticism in the service of inclusiveness and clear language is one thing; literalist nitpicking is another. When we say "The picture isn't real," I think it's rather clear from context that we mean "the picture is not a veridical rendering of reality," not "the picture does not exist."
On the other hand---it is worth pointing out that men viewing pornography should not be said to be making a mistake (as is suggested by speaking of a "feeling of horniness {being} not connected to what’s in reality"). The men know perfectly well that it's only a photograph, they just don't care. Why would they or should they? Humans are adaptation-executers, not fitness-maximizers.
All this mess could be sidestepped entirely by using "sunset/beautiful" or "chocolate/tasty" rather than "Jessica Alba/sexy," although I imagine some would argue that this would damage the presentation by making it less entertaining.
I also note that using a photoshopped image (or playing the Dove natural beauty youtube thingy) would convey the point even more strongly.
Here is a 2-hour slide presentation I made for college students and teens:
You Are A Brain
It's an introduction to realist thinking, a tour of all the good stuff people don't realize until they include a node for their brain's map in their brain's map. All the concepts come from Eliezer's posts on Overcoming Bias.
I presented this to my old youth group while staffing one of their events. In addition to the slide show, I had a browser with various optical illusions open in tabs, and I brought in a bunch of lemons and miracle fruit tablets. They had a good time and stayed engaged.
I hope the slides will be of use to others trying to promote the public understanding of rationality.
Note: When you view the presentation, make sure you can see the speaker notes. They capture the gist of what I was saying while I was showing each slide.
Added 6 years later: I finally made a video of myself presenting this, except this time it was an adult audience. See this discussion post.