The "other thing" is literally just child pornography through and through, photographs or videos of real children engaged in sexual activity.
The fact that the author has neglected to specifically state the difference is strange, and I honestly can't think of a good reason for doing this, or why it was left in Japanese script.
Furthermore, there's something else here; a while ago I read an article which claimed that 81% of the Japanese public based on an extrapolated study would be fine with lolicon being made illegal. So how does the author say that lolicon being acceptable is a mainstream view? The author writes too,
>The idea that ロリコン is bad in the same way 児童ポルノ is bad, or even that there could be a meaningful category including both ロリコン and 児童ポルノ as if they were somehow comparable, is incomprehensible from the mainstream Japanese point of view.
Does this make me an honorary holder of the Japanese point of view? I honestly can't see a way in which drawings and real life photos in this case are comparable at all, it's incomprehensible to me how one could lump them together other than by the subject matter they represent, which is extremely broad and ignores the whole point of the classification - that is, one necessitates child abuse to be created, and the other doesn't. I very much align with the Japanese point of view here.
On the other things the author mentioned, I agree with another commenter in saying that it's not at at all useful to frame this as "red" and "blue"; I consider myself rather "blue" on some issues (being a socialist) but the liberal idea of free speech is one I hold very dear to myself, and I am vehemently opposed to laws that target any kind of expression, even if that does entail "lolicon"; I believe the harm principle can stand here on its own, though I'm not sure if I'd bend even if it was proven conclusively (how?) that lolicon "causes" people to molest real children.