Microsoft"s OneNote app on iOS is getting an update, which allows you to set images as the background in your notes. All you have to do is press and hold on the image for the popup menu to appear, and tap "Set Picture to Background".
Once this is done, the image is part of the background of your note. You can type over it, write on it with inking, and even place another image on top of it. It no longer functions like a regular image in OneNote.
It seems that after setting an image as the background, there"s also no way to get the context menu to appear again, so once it"s the background, you can"t easily go back.
If you want to check out OneNote on the App Store, or update your app, you can find it here.