Spencer Hastings in 3.1 Phillip Lim in 1x01, “Pilot”.
So I haven’t found any other bloggers post this item, so I’m not 100% certain this is exact, but I do believe this is the 3.1 Phillip Lim Ruffle Back Cardigan. If you look at photos #1 and #4, you can definitely see the similarities in the buttons, hem and the way the ruffles stick out in the back. In #2 and #3, the scattered look to the ruffles are very similar, though I think that #2 is the “boyfriend fit” and #3 is the traditional women’s fit.
Unfortunately the actual top is NLA, but there are many ruffle cardis on eBay, including this cute one (#5) that is sooo Spence!
Look for less: