Most people who have not seen this before would estimate that White has the larger territory, but count it. White has 11*11 = 121. Black has (38*2) + (30*2) = 136. So, not only has Black won, but she has won quite well. Now, of course, this is a very artificial situation, and could never occur in a real game. For one thing, Black has played 56 stones while White has only played 48.
Beginners may wonder whether White can invade the Black territory and make a living group. I'll just say no, but try to figure it out for yourself. In fact, if Black ignores White's move six times in a row, it is possible, but very unlikely.
[Can Black invade White's territory and live? Probably not: it would be like playing on an 11x11 go board when the edges are not "friendly" any more. I set this position up on a simple Go-playing computer program and was able to form a living Black group inside, but I feel sure that a strong player would have been able to stop me.]
This is a good illustration of a famous Go proverb: "the middle is always smaller than it looks." The fact that this strategy of "running along the third line" works on a 19x19 board means that it would be even more effective on a 13x13 or 9x9 board, where the middle territory would be even smaller.
Let's imagine that Black wants to create the situation in the diagram. As a first play, he takes a 3-3 point, at 1 [C3], which is a common opening, and White plays on top, which is the most common response. Black continues by moving along the third line, and White follows along, Up to this point this is all very conventional.
Now let's assume that Black wants to continue along the third line, White could play 6 [C4] and ensure that Black cannot get the third line along the left edge...
But that might lead to Black playing 7 [F4] and pushing along the fourth line
Now, if the third line is called the Line of Territory, the fourth line is called " the Line of Victory," (or sometimes "the Line of Influence." So - in this area at least, Black's expansion to the right is likely to be very profitable.
White will therefore probably not play 6 at C4, but at F3 instead, with a continuation like this.
Black still has the possibility of extending along the third line on the left-hand side, but the extension to the right has been pushed down to the second line, and, as you may imagine, this line also has a name. It is called "the Line of Defeat." White can continue pressing Black down with 10 atH3 (or even H2) and Black's final position will not be satisfactory.