The browser version allows me to add key images from papers to my annotations list via a box select function. However, when I am reading papers on the iPad app, this is not an option. I think having that available on the app would be nice as I do most of my reading on the app and then use that info for research in the desktop browser.
Welcome to the Paperpile community, @Kayla_Dempsey, and thank you for sharing your feedback! Knowing that you want to create shapes in the mobile PDF viewer to highlight key images helps us better understand your use case. I’ve recorded your thoughts, along with your +1 for this request, on our internal feature tracker for the team’s consideration.