Thank you for your interest in NodeXL!
Subgraph images are rendered in a "schematic" form but you can accomplish what you want using the Export menu "Export Selection to new NodeXL Workbook". Using the right click menu select the "Select Subgraphs" when you
click on a target node. This will allow you to select a node and its neighbors out a specified number of steps. This subgraph can then be pushed out into a workbook of its own.
I believe that sub-graphs that are written to individual images do render in the fully formatted layout, we keep the thumbnails simple to avoid "blobs".
I hope this helps, let us know if it works for you!