Can
It's kind of hard to see, but if you look at this the right way it looks like a food can. See the lid being pulled off in the top-left corner? And that horizontal line in the middle? That’s the can's label.
An update is needed before you can continue but you have more than one WaniKani tab open.
Finish up what ever you are doing on the other tab(s), then close them to continue.
The update will complete automatically once the other tab(s) are closed.