you only get points each week depending on your place, the common pvp arena rests every Monday 10:00 Tokyo Time.
According to your picture you where around rank 1500 so you will get 1 point for this week.
You got 3 so you will have 4 and need another point the get the reward displayed.
The current event is a pvp event, you get rewards according to how much points you earn. Every time you defeat someone in the arena you get one point and the rewards are handed out depending on how much points you reach. The event goes till 01.09.14.
Also on a side note, seems there are no new cards and they are the same cards that where available during last event.
First SR card is at 500.
The interesting rewards are bascially at:
50 gatcha
150 HR gatcha
300 gatcha
500 SR gatcha
1000 gatcha
1250 gatcha
1500 HR gatcha
1650 gatcha
2000 3xgatcha
2300 gatcha
3000 SR gatcha
I only aimed for 150 last time, because its not worth it to go further, you need to spent shitload of money to get above 500. People how saved lots of BPs might the the first SR gatcha but hard to tell if people actually saved so much.