It might be interesting to do a separate one just on Instagram. I have no idea what half of the trending hashtags on Instagram means and a picture speaks a thousand words.
But I agree, a separate one analyzing the pictures could be valuable as well. However, Instagram pictures often don't contain much text apart from a wall of hash tags. So the text might not be super important to analyze. Anyways, picture analysis might be slightly more difficult and more resource intensive than text analysis, but very interesting as well.