They. They put a boob jiggle. On a solid piece of metal armor.
While the OP’s gif arguably shows the whole booblate moving up and down instead of just the breasts jiggling (so it’s not improbable… given the armor is really badly fitted and worn with zero chest support), it gets worse…
Yeah, don’t kid yourselves, rebloggers: that character’s boobs do actually bend metal around them. It’s just not all that obvious in the top gif.
Now, I agree that boobs are great, but if you’ve investing this kind of effort into showing them jiggling through armor then you may want to consider shifting genres. I mean, this goes well beyond Schrodinger’s Breasts.
And yet is still so, so far from the worst.