Sorry to butt in, but I was passing by and I think I might know what's not working for the person who asked you to cut.

From what I'm seeing, you used a spoiler cut. Those don't show up for people on mobile devices for some mysterious reason to do with LJ being LJ. I believe LJ cuts do: change "lj-spoiler" to "lj-cut" in the opening and closing html, and it should show up as a cut for everyone. I think! I'm not a mobile device user myself, but I've heard a lot of people mention the spoiler cut issue.

Hope that helps, and welcome to LJ. I've found this