Found it.
Taken from the Hamodia website.
Some people say that the well-known portrait of the Chofetz Chaim disseminated widely today is not accurate and that there is a snapshot of him sitting outside his home in Radin. Do you remember which image the Chofetz Chaim resembled?
I remember the Chofetz Chaim as he appears in this portrait [pointing to the standard image hanging on his wall]. It seems that in the 1920s the Chofetz Chaim still looked like he does in this portrait, but maybe later on he became very weak and frail and his age was more apparent, like in that photograph of him sitting outside his house after his doctor instructed him to go outside for fresh air every day.
Here is the whole article.