How can I plot an image centering in a branch ( or "arm" or bracket) of a dendrogram?

I would like to plot several images each one centered in the branch of the same dendrogram, so for a branch(call like this is correct?) [ i have to plot 2 images, each one centered in the corner of it. something like this

http://www.google.com/imgres?start=104&sa=X&es_sm=93&biw=1044&bih=621&tbm=isch&tbnid=mL5I-vOplla0uM:&imgrefurl=http://www.ait.edu.gr/ait_web_site/faculty/apne/Face_Recognition.html&docid=gLWPewYZ1sbeEM&imgurl=http://www.ait.gr/ait_web_site/faculty/apne/Images/dendrogram.jpg&w=589&h=340&ei=37NVUvqvH4m29gTdhIDoCw&zoom=1&ved=1t:3588,r:15,s:100,i:49&iact=rc&page=8&tbnh=170&tbnw=296&ndsp=13&tx=129&ty=77