There are four types of seasonal reward. You will receive a reward at the end of the Season, based on the highest trophy amount you achieved. The Bronze Reward goes to players who achieved a trophy high between 2500 and 2799 trophies, Silver Reward for those between 2800 and 3099, Gold Reward for players between 3100 and 3399 and the Diamond Reward goes to those who got 3400+ trophies.