The socket looks "empty" (Fig.2 S, basis for osteotomes).  It consists of the buccal (pink dashed line) and palatal (red) ones (Fig.3).  In one word, the socket is pyramidal.  It appears that a tapered implant is appropriate for the site.

Osteotomes

Xin Wei, DDS, PhD, MS 1st edition 06/08/2015, last revision 06/08/2015