Large-shouldered tops were popular in the United States in the 1980s because by that time the effects of feminism had trickled into professional environments, and women wanted clothes (specifically, suits) that made them look more commanding, more assertive - more traditionally masculine. Towards that end, I am sure they were successful; but I am equally sure that they did and still do make women much less attractive. And now, partially out of nostalgia for the fashions of a former generation, and partially due to social inertia, contemporary style calls tops with "puffy" or accentuated shoulders acceptable, "fun" or even attractive. Don't be sucked into the lie. The truth is that they are always risky, usually ugly and almost never a good idea.
If you think any of the women on the left look attractive, read the post titled "Because Of" vs. "In Spite Of". (All three are in good shape and their clothes fit well in all places but the shoulders.)
Clothes that slightly accentuate the shoulders might be mildly attractive on a girl that does not have a small waist-to-hip ratio; but in general, large shoulders make you look like a man and should be avoided.
Remember: whether consciously or subconsciously, men notice.