The reason why we had a wide-bodied Estima (Previa/Tarago) and the narrower Estima Emina/Lucida can be found here:
Estima Motoring Community - Model Info - Estima
The Emina & Lucida are almost totally the same - save different front ends and small changes at the rear. Mechanically, dimensionally and internally, they are identical. The reason for having two models was down to Toyota having 2 seperate Divisions market the car - having the 2 models meant that Toyota could have seperate stats for each. (If you want to go deeper into the reasoning, ask Toyota!)
The easiest way to ascertain if an Estima is an Emina or a Lucida (bar looking at the badge on the tailgate! :
), is to look at the front end: