Earliest Known Texting Photo?

Wikipedia's text messaging article provides a detailed history of texting. Although there were antecedents--telex in 1933, ALOHAnet in 1971, and even wireless telegraphy in the nineteenth century--it wasn't until 1995 that Sprint Spectrum introduced the first modern text messaging service (SMS, or Short Messaging Service) in Washington, D.C., and Baltimore, Maryland.

I think that this chronology will have to be revised, however, since I'm pretty sure that this old photo shows a kid texting away on his phone while his brother and mother wait for him to finish. Unfortunately, the picture isn't dated, but since the boys are wearing knickerbockers. I wouldn't be surprised to learn that it was taken as early as the 1910s or 1920s.

I wonder if any other texting photos from the early twentieth century have survived.