BERLIN (AP) — Climate activist Greta Thunberg has tweeted a photo of herself sitting on the floor of a German train surrounded by lots of bags — an image that has drawn plenty of comment online about the performance of German railways.

Thunberg posted the tweet late Saturday with the comment “traveling on overcrowded trains through Germany. And I’m finally on my way home!”

Some Twitter users pitied the 16-year-old Swedish activist for not being able to get a proper seat on the train for the long ride home from Madrid, where she was attending the U.N. climate change conference. Others wished her a safe trip home after months of traveling by trains and boats to different climate events in Europe and the United States.

Thunberg doesn't fly on planes because it's considered harmful to the climate. Last week she was named Time magazine's Person of the Year for her efforts to prod government and others to take faster actions in fighting climate change.

German railways Deutsche Bahn, which used to be famous for its punctuality, has come under fire in recent years for delays, last-minute train cancellations and expensive ticket fares.

Deutsche Bahn replied to the teenager's tweet, wishing her a good trip back home and adding that “we continue working hard on getting more trains, connections and seats.”

In the picture on Twitter, Thunberg is sitting on the floor at the end of a rail car with her back leaning against a suitcase, staring out of a window. There's an empty food box next to her and more suitcases and backpacks piled up by her side.