Closure phases as a function of the time of observation, detected on the APEX-SMT-JCMT non-trivial triangle, compared with the predictions of the model presented in this paper. Error bars indicate the 68% confidence level. The best-fit model 2g with two Gaussian components representing the compact emission region fails to adequately capture the trend in the data, unlike the 3g model with three components. The reported χ² corresponds to the non-trivial subset of all measured closure phases.