We explain them by telling them the purpose of what happens in the Temple, and the nature of what happens. There’s nothing secret about any of it, though I doubt that you will accept that idea. It is, however, sacred to me, and I will not discuss them with you for the reasons I mentioned.
There are many pictures on the internet of Temple interiors. The nature of the promises we make are explained. The reason we make these promises is explained. People are told that the Temple experience is very different from the everyday LDS meeting; extremely scripted, loaded with symbolism, and extremely dense in meaning. Since nothing is taught in the Temple that is NOT taught elsewhere, the only reason I can see for talking about the details is to satisfy voyeuristic curiousity…and by doing so, belittle the very special religious and spiritual nature of the experience.
If you want to dismiss it as ‘like freemasonry’ go right ahead, The ceremonies have some similarities in feel, I suppose–or so I have been told. (shrug) it is my faith, and frankly, you do not have the right to demand that I go against it in order to satisfy the itch of antis to make fun of it.