Kat,
A recent discussion had this idea and a solution for images and sketching over. But anything could be designed.
You may find describing the feature you want, rather than assuming people know what One Note Highlighting is. The fact is to my understanding that highlighting in one note is in edit mode, you still have to edit the [note] and then scroll down to the point in the article and the visual editor Mark pointed to allows this WISYWIG editing. It uses a ckeditor and needs some locally installed support software, from memory.
In tiddlywikis (text) edit mode you can highlight text and press a Editor Tool bar button to apply highlighting, and you can use preview mode to have the edit window and the preview window open at one time. Im am not sure if this is default or a plugin, if you are interested I will look for it.
Your request has given me an idea that a review mode would be nice where you read Tiddlers in view template and can only apply simple highlights and comments to the underlying tiddler. I use FoxIt reader for PDF annotation and could see value designing something similar, although there are technical challenges.
Regards
Tony