It is much rarer to see images of photographers themselves, instead of their friends, family or acquaintances. Perhaps that reluctance stems from a self-consciousness that they felt more comfortable behind the lens instead of in front of it. Of course there were some notable exceptions: Nadar was notorious for his self promotion and many self portraits.
Most of these images were simply self portraits. Only a few were taken by other photographers. Again, the reluctance to be taken by others may be an exhibition of ego or just a shyness--and the portraits show both emotions readily. Some photographer sit for their portraits in pompous splendor or in retiring simplicity.
Photographer's portraits were made almost from the beginning. Hippolyte Bayard's bizarre joke of an image of himself as a suicide victim (because the French government had not recognized his pioneering efforts and had given pensions only to the Daguerre/Niepce team) was certainly an early and rather startling portrait of the artist.
In these examples from both the 19th and 20th century, you will find photographers who pose with their equipment, who are in the process of shooting themselves, who sit or stand stiffly for formal portraits, or who pose casually. Some, like Duc de Massa and Franck Chauvassagne, dress up in theatrical style. Others, like Margaret Cressman, shed their clothes completely.
But I find all of these images to be very revealing and shed an interesting spotlight on who these artists really were/are. Many are famous names and others are just minor footnotes in the history of photography, if known at all. But all show personality.