Question in "Marginalized Gaussian Mixture Model"

I was trying to sample from the model’s posterior predictive distribution, as in following URL.
Marginalized Gaussian Mixture Model

I used the same code except my seaborn parameters.
What is a cause of this duplicated plot?

Thank you in advance.

↓Result I got.

↓Expected result.

You should get something like (see the updated doc)
As the posterior predictive distribution contains uncertainties.
You can computed the mean of the posterior predictive samples if you would like to have a plot like “Expected result”