Please help me. I'm wondering what this phrase "I see what it is about" mean? And please show me that what context can it usually used in?
And this is the context:
A: You know, ever since college it's been, Marshall and Lilly and me. Now, it's gonna be Marshall and Lilly... and me. They'll get married, start a family. Before long, I'm that weird, middle-aged bachelor their kids call Uncle Ted.
B: I see what this is about.
(Source: How I Met Your Mother, Season 1, episode 1)