See http://dev.w3.org/csswg/css3-flexbox/#table-items. On a flex item with ‘display: table’, the table wrapper box becomes the flex item, and the ‘order’ and ‘align-self’ properties apply to it. The contents of any caption boxes contribute to the calculation of the table wrapper box's min-content and max-content sizes. However, like ‘width’ and ‘height’, the ‘flex’ longhands apply to the table box as follows: the flex item's final size is calculated by performing layout as if the distance between the table wrapper box's edges and the table box's content edges were all part of the table box's border+padding area, and the table box were the flex item.