What is the message the Chinese are trying to convey?

The Chinese are arguably Sub-Saharan Africa's biggest trading partner. They are Ethiopia's, too. I have no problem with that. But I have a problem with their way of doing business in Ethiopia. For example, take a look at the picture below from a Chinese shoe factory that opened in Ethiopia last year. What is the point of writing the messages in the ceiling of the factory, which seem to be directed at the workers, in Chinese? Okay, I see some Chinese managers working there. But, isn't the factory located in Ethiopia? Doesn't it make sense to have the message written in Amharic first, and then in Chinese or English? Why is the message in Chinese written in bigger fonts compared to the messages in Amharic and English? What is the message the Chinese are trying to convey? Isn't this a manifestation of an unequal partnership between the Ethiopian and Chinese sides? If so, I think this is a sign of an unhealthy partnership and it must change.