In responsive view position of pictures change

Hello dear friends, i noticed that in responsive view the position of the pictures are changed like on the description. Website is: http://t1p.de/0ax4 [1] [2] [3] [4] [5] [6] and so on, changed to [1] [2] [3] [4] I don‘t like this. It should stay always in dobble Box. How could I change? Thanks for Support