So, I'm getting around to playing Myst 5 and I'm in the telescopy world, almost done. I wanted to show my friend the faceless rock monkeys that come to take my slate away, so I drew a happy face on the slate, thinking the monkey would look at it and go "huh?" and go away.
Instead it took the slate, and a new symbol appeared on the rock stand, a circle with an orbiting smaller circle. Apparently the game misread my drawing and skipped me ahead a big bunch.
Is this a bug or what? So, I'm going back to do the tram thing just to do it, even though I officially, according to the game, solved this portion of it.
Yes, that is a well-known bug. In fact, you should never draw anything on the slate except the symbols that are clearly meant to be drawn. The problem is most apparent in Todelmer (the astronomy age) but it occurs in other ages too.
Unfortunately, since Cyan (the developer) and Ubisoft (the publisher) don't work together anymore, it is unlikely that this bug will be repaired.
As far as the game is concerned, you have accomplished your goal in this age, so you can go on to look for the remaining ages now.
If you wish, you can go back to a saved game (i.e. a picture taken with your 'camera') from before you drew the smiley, or start a new game if you want to complete the age the 'proper' way. But there'll be no negative consequences if you don't.