Re: Emacs manual mentioning thumbs mode but not tumme

[Richard Stallman]

    > It is the conceptual cost for users.

    Not so when the explanation for the existence of thumbs is so concise.
    The user is guided and recommended to tumme and in one sentence you
    could mention thumbs as an alternative for image viewing.  The user
    has then the option to experiment.

That IS a conceptual cost.  It means that instead of a simple and
clear recommendation, we say "maybe this, maybe that."
Users can find this confusing.