Sliding an Edge or Vert w/o stretch/pinch texture image?

[Fonte Boa]

Misty,
it is simple: two objects.

The first one, an image plane, you will use just to show you an image. You will use it as reference, an image projector: you wont manipulate its verts or edges. You can lock it at Geometry Graph window to avoid modify its topology.

The second one you will reshape (by manipulating its vert, edge, face, moving, scaling, rotating) using the first one as visual guide. This way, you will be able to build your tree by putting the elements in the right places until this object seems like the image shown in the first object.