The mod that looked a lot like Diana (Alina Vacariu also in certain poses) is Andrea Krakhecke, a Brazilian who also appears in Elle Spain now and then...
Kasia Smutniak confused me only once, but it was because they styled her to look like Diana, here:
(Admin, it's my site, it's OK to hotlink to myself - I think...)
Note the same Diana pose, in this Rocco ad (Wendy D in the background)
Diana Rocco ad
and I had that look embedded in my brain from back in 98...
Diana pic from Nice, France