It looks like the game got confused & superimposed a Sim thought bubble, over the "I can't reach an object to interact with it." bubble. You can see the other thought bubble, faintly beneath the airplane one. Now, I've always been curious about those bubbles. Typically, they're supposed to represent your Sim's [Seemingly random] thought processes. However, I bet there is probably some significance to the bubbles, that the devs use for diagnostic purposes. I would be curious to know, whether the bubbles could be used, to interpret moods, that don't necessarily create moodlets. Sometimes, the bubbles seem to match the situation, beyond indicating that a Sim is thinking about the Sim that they're talking to.
My guess, if the bubbles do mean something, is that your Sim is probably thinking of travel, or would like to see a new place.
