Personally, I'm not on Serena's side over this fiasco. She's mostly in the wrong, although there is certainly a school of thought that umpires/referees should not choose actions that greatly affect the outcome of major sports events. In many sports, superstars get superstar treatment. Although I personally believe Serena pulling the gender card is bogus, it's fair to ask why did the chair umpire choose the US Open final to impose code violations? A worse example IMO was in 2009 when Williams was called for a questionable foot fault at 0-1, 5-6 against Kim Clijsters (after which Williams lost it and blew up). Does this type of random ticky tack shit happen to other tennis legends? As Darwin333 said, could Carlos Ramos at any point have warned Williams to back off or face penalties? I do feel Williams grossly overreacted towards Ramos, and that by the letter of the law, he didn't do anything wrong.
Having said that, some of you are tools for not seeing that cartoon as problematic. At best it's an innocent caricature. I rarely pull the "because we're American card" but we're supposed to take Australians' word for it that there was no bad intent? I can accept at face value Knight's assertion that there was no racial intention. But why does it matter that other Australians were highly disappointed in Serena's outburst?
I'm no SJW, but the question is whether the cartoon itself is problematic. As Brainonska511 is saying, look at how Serena is portrayed. And then Haitian-Japanese American Naomi Osaka is apparently turned into a fair-skinned blonde. It's hard to imagine that the editorial department of any major U.S. newspaper would approve this cartoon as is. It may not be intentionally or overtly racist, but there is history/context in the U.S. to consider.
But since the Aussies say it's OK, I guess we should all be cool about it...