How does the phrase "envy and and pride grew higher and higher in her heart like a weed" from paragraph 8 contribute to the meaning of the story?

In context, the Queen is reacting to the "looking glass'" answer to her question. Previously, the looking glass had always proclaimed the Queen to be the fairest of all. When the looking glass gives her a different answer, the Queen is filled with jealousy and rage, and she subsequently sends the huntsman to rid her of her rival. This speaks to the destructive nature of jealousy.

This gave the queen a great shock, and she became yellow and green with envy, and from that hour her heart turned against Snow-white, and she hated her. And envy and pride like ill weeds grew in her heart higher every day, until she had no peace day or night. At last she sent for a huntsman, and said, "Take the child out into the woods, so that I may set eyes on her no more. You must put her to death, and bring me her
heart for a token."