Hey there Isabelle, I am the one that was assigned to check out your article additions. I really like the way your writing is worded, it comes across very direct and fact driven. I feel that that is a common theme in Wikipedia articles, that was a challenge that I faced while writing my own, trying to 'match the mood' of a Wiki page.
You gave some clear descriptions on the objects that you were assigned to research, If your original article was anything compared to mine, there wasn't much information there originally, so I am sure your definitions were really needed.
I think it is good that you chose to add the information that you did instead of trying to file into adding more subheadings in the article.
I don't think that another picture reference could be good, to break up some of the larger chunks of writing that you have in the first paragraphs.