I love questions like this! It's all about the proportions, right? And possibly fabrication, as well. But this reminds me of our straight leg vs. tapered and tapered pencil vs. straight pencil skirt conversation.
I like this top on you -- it is easy. The fit glides.
I don't have an absolute answer. But I suspect it relates to what Julie said, above, combined, perhaps, with other fit elements of the other drop-shoulder sweaters you've tried.
For instance, neckline. This one has a very open neckline. Were those other sweaters higher or snugger in the neckline? That would change the effect completely.
Drop shoulders with a very open neckline will not work on me, whereas those with a neater or more closed neckline are much more promising. I can do a drop shoulder boatneck (if the fit is neat) or a mock neck, or a shirt collar or similar. But if the neckline is as open as this it will always look sloppy on me. (So perhaps the opposite of you.)
It may also just be a question of structure, i.e. showing some skin and bone. In this style, we see your arms and neckline clearly and that adds structure to the ease.