ノードに画像を描画

## image
rasters <- c();
for(v in V(g)$name){
  jpg <- paste("/Users/ukonlly/data/", v, ".jpg", sep="");
  url <- paste("file://", jpg, sep="");
  
  if(file.exists(jpg)){
    con <- url(url, open="rb")
    bin <- readBin(con, what="raw", n=10^6)
    close(con)
    rast <- readJPEG(bin, native=TRUE);
  } else {
    rast <- as.raster(matrix());
  }
  rasters <- c(rasters, list(rast));
}
V(g)$raster <- rasters;


## plot
plot(g, vertex.shape="raster",
     layout=layout.auto,
     margin=.2,
     edge.label.family="Hiragino Kaku Gothic Pro W3", 
     vertex.label.family="Hiragino Kaku Gothic Pro W3",
     vertex.size=8, vertex.size2=8,
     vertex.label.dist=2, vertex.label.degree=0,
);

参考

R : Display Image at Exact Node in Igraph - Stack Overflow

Facebook data collection and photo network visualization with Gephi and R