We cannot know what feedback and which comments make the student work in the right direction.
But experience learns (but she is not infallible) positive feedback often is better than no critique or negative remarks.
Here is a cultural difference in giving positive comments. Some people do use strong words in their positive remarks. (love it, and great, amazing) We like that very much. Some people are less exaltic. We need to know who says what to know this.
Some feedback does show much attention and interest for the work “The leaves and berries make for a nice composition, with great colours.”
It is difficult to give positive comments and make someone’s work of art better.
“this would be still better if you did that..” That takes courage. (Mvdfunes and johnjohnston on ds106radio 12oct2014, I do not know an archive of that, do you know that archive?)
I like the idea of remixing as a way of critique. One could just remix her art, and give critique totally non-verbally. Anna Cow did some remixing to try this idea. She did remix Sandy Browns tds1002 letterhead into a letterhead of her own. Critique and feedback are closely connected to trust.