Occasionally, tiles covered with a diamond shell may appear in the Picnic levels. You need to collect such tiles first before they expire. The diamond tiles are destroyed with each move you make in the level. Each diamond shell is completely destroyed in four moves .

After a diamond shell is destroyed, the tile becomes a regular tile like all the others. If you fail to collect the diamond tiles before they expire, the level will not be lost, but you will not receive additional rewards.