Calling players out
The issue with Ozil is telling. But we don’t know for sure if there was a fight between him and Emery, or if he was indeed ill.
However, if there was a confrontation, then it shows that Emery is keen to ensure all players adhere to his philosophy. Emery himself said that Ozil had a cold - or "catarro" in Spanish. However, it is ultimately rooted in speculation, and it may or may not show that he doesn't pull punches when needed.
Learning on the job
He is indeed learning how to speak English, and this in contrast with Wenger, who is fluent in multiple languages and thus a polyglot.
However, Emery must be commended in adapting, and showing the willingness to advance his English skills. This is essential, especially given the complex details he wishes to convey tactically.
After the recent win at Cardiff, Emery seemed pretty lucid. He does occasionally need his interpreter, but it shows he's willing to get dug in, as it were. With improving English skills, it can bode well for relaying his plans to the players, and enhanced tactical skills.