Was that a cue to talk to somebody who's now watching?  Well, won't hurt if she makes a mistake about that.  She repeats the gesture, pointing at herself.  "Thellim!"  Long pause.  "Language difficulty!  Tsi-imbi!  I'm from dath ilan!  As you can see, I speak an unknown complicated syntactical language with at least some repeated words, if I go on talking long enough I ought to at least repeat a preposition or something, so unless your first theory is that somebody devised a whole new language and learned fluency in it to the point of doing this as a prank, I probably come from another world!  Though I'd totally understand if you thought pranks were a higher prior probability than that.  I hope your world gets lots of people like me and that you do not start out with an astronomically high prior that everyone here is insane!"

Was that a cue to talk to somebody who's now watching?  Well, won't hurt if she makes a mistake about that.  She repeats the gesture, pointing at herself.  "Thellim!"  Long pause.  "Language difficulty!  Tsi-imbi!  I'm from dath ilan!  As you can see, I speak an unknown complicated syntactical language with at least some repeated words, if I go on talking long enough I ought to at least repeat a preposition or something, so unless your first theory is that somebody devised a whole new language and learned fluency in it as a prank, I probably come from another world!  Though I'd totally understand if you thought pranks were a higher prior probability than that.  I hope your world gets lots of people like me and that you do not start out with an astronomically high prior that everyone in this house is insane!"