hmmm followed the ingame walkthrough and so many scenes were missed. Going by the pictures the 2nd from the top that scene never happened. I even remember a choice for her that said something about a scene in the future but it still never happened. Even the 3rd picture from the bottom with the strap-on never happened.
The scenes you miss by following the in-game walkthrough are either story dependent or variant of scenes for situations in which you are not romancing every girl (for example, instead of a threesome with Emily and Alex you get a scene with only Alex or only Emily).
The PDF walkthrough has a section with all the scenes and how to unlock them.