For each of the individual columns select the pencil edit button > Response Options.

For the bottom mobile device leave Offset set to ‘No Offset’, but set the width to match the column width. So for instance for a 4 column row set it to ‘3 columns’ – 1/4 (its the 1/4 which we want, the 3 columns in this example is because the columns is always based on a total width of 12 regardless of how many you are actually using, so 1 column would=12.

If you have an image in the column it will now shrink with the column as the scrteen width gets too small