Stand back: you're about to feel the full-on glamour of two legendary film queens.
Feel the luminescence!
But that's not the full story: After the poster solicited comparisons between the two actresses, one commenter wrote, "Joan Crawford looks way better in my opinion more classic and refined and Julia is wearing ugly black nail polish."
Well, today's modern royal screen highness was not going to let that stand.
Roberts, who only joined Instagram in June, clapped back, to the delight of her fans. In her reply to the original comment, she wrote, "It is in fact a navy polish with garnets crystals as a grounding accent. In case you would like to edit your comment from 'ugly black nail polish' to ugly navy polish with Garnet crystals. Just sayin''
And then she included a little emoji of fingernails getting painted!
Now, we're quite sure Roberts, 50, has many exciting things to do like walk more red carpets and dazzle us with amazing gowns. (She was in Toronto to promote her upcoming Amazon series, "Homecoming.")
But if she takes the time to occasionally shoot down a troll here and there, we're totally prepared to cheer her on.