Which graph? There are several. I believe you’re looking at the one that crosses 10C? It’s “flat for all the recent data” because the data set for that graph only goes back 15 years. That’s a pretty restrictive data set to declare the temperature is “flat.”
I believe the author, like many others, is making the assumption that people reading the article have a mental picture of the observed worldwide temperature curve (including ice core data) going back to pre-industrial time, which looks remarkably like a hockey stick.
The hockey stick is going to start looking more like a scythe Real Soon Now.