A slant style tree is an upright tree whose apex is not centered over the roots. The first branch can go in the direction of the slant, or backwards for "balance".
They can be made either way. The Japanese tend to favor the first branch on the side going with the slant, as someone earlier said, "reaching for the light". Westerners tend to prefer the first branch going back the other way, "for balance". Either way can work.
Usually stands will have some movement in the trunk. A perfectly straight trunk growing at an angle looks like a tree halfway falling down.
Darlene, your trees are cascades or semi-cascades. There just too much foliage below the rim of the pot for them to be considered "slant". And indeed, if foliage hangs below the bottom of the pot it's not a "semi-cascade". As for the fact the trunk starts off at an angle, how else could a cascade be?