That could be true. Violet enjoys taunting Barb and trying to provoke her. As Violet stated after their fight in the dining-room, "I was spoiling for a fight, and you gave it to me."
It reminded me of the scene in
Affliction
between Wade and his bitter old father, when the old man says "You're just like me". Wade goes "No, I'm nothing like you…". And the old man goes "Yes you are". The old man had a kind of malignant pride that his son was as bad as he was. Some people are like that.

The points being made are good but I don't think that Vi is trying to control her. She does that because she is the only one in her eyes worth of doing a thing. And she loooves the little cuts that Barb finally starts to make towards her like 'or we can just wait for your funeral and have it for free' or 'you're a drug addict'. That's what Vi ultimately wants from her : the beast to come out and claim its presence. Otherwise, in Vi's complex mind, she's not living up to her potential.

I read these message boards because I am a black/white, "I see the forest, not the trees", person. Message boards help me to get more out of a movie than I can alone. Symbolism is lost on me. Vi asking Barbara confused me, too. She (Vi) walked into the room and was standing only a step or two away from "there." Couldn't she have set the picture down? But that was the end of my thoughts on the matter. The Vi controlling Barb perception helped me make sense out that scene and other scenes. I enjoy a more in-depth understanding of movies than I give myself. I thank you.

Good point. Didn't look at it that way and I believe you're right.

Barb is Vi's favorite. Vi wants to control her, and ordering her to do things is an attempt at control. Complaining that Barb never comes to visit, and that she couldn't come home when Vi got cancer but rushed right back when Bev disappeared, is another.
Meryl Streep is a shape-shifter.