Thank you for the interest in NodeXL!
To set a Twitter network vertex to display a image as its shape, the "Vertex Shape" must be set to "Image".
This can be done easily via the NodeXL>Visual Properties>Autofill Columns>Vertices>Vertex Shape setting.
NodeXL can handle data volumes in proportion of hardware resources: more RAM is good!
8GB systems can easily manage 10K edges.
16GB systems can manage as much at 100K edges.
We have been successful with networks as large as 250K edges on systems with 32 GB of RAM.
The types of network displays created by NodeXL that can be seen in the
can be recreated easily using the "recipe" feature in NodeXL.
At the bottom of many graphs uploaded to the NodeXLGraphGallery you will find the "Settings" used to create the graph.
Download this file. Use NodeXL>Options>Import to load the settings into NodeXL.
Apply the settings using NodeXL > Graph > Automate > Run.