^ Two things, I think.
1) In the original rendering, the podium was only wider than the tower on one side; on the other side - the side facing front in the rendering - the tower had a sheer edge all the way up. Geometrically striking. In the new rendering, the tower is perched on a squat-looking base, deprived of its sharp edge. This is a bona fide design change.
2) In the old rendering, the glass curtain was very conspicuously divided into horizontal bands, each about three storeys high. It gave the impression of being a stylistic feature, though it was probably just a quirk of the renderer. Now that the tower is rendered as being banded only by each floor, it seems uniform and bland.
3) The curtain seems to extend might higher past the roofline in the original render, though that might be a function of the miserable lenses that every tower rendering is shot through, giving them the impression (most noticeably with B/A) of actively leaning out from the curb.
4) Remember that this wasn't the only rendering we saw. Others painted similar pictures of a luminous, transparent, avant-garde design.
I see Ganj's point, and generally agree: why anyone gets excited about renderings anymore, after Harry's glowing blue speed-stick 1KW, and the luminescence we were supposed to get out of ROCP, is beyond me. All the same, there were some definite changes here, and for the worse.
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