Cannot add images to blog post

Site URL: http://www.thefavoredend.com

Hi:

I have a small SS website and post to it infrequently. I just put up a blog post (still a draft) and want to add some images. When I click on the "+" between paragraphs all I get is a blank box that I believe is supposed to open to allow the posting of photos, etc... Am I missing something? Screen shot attached. 

Try Chrome vs Safari.