Same painting. A picture for those who want to compare:

From the
Canada's Postage Stamps book by Douglas and Mary Patrick (published 1964), with regards to the 3-cent brown issue of 1917:
Quote:
"The Fathers of Confederation" from a photograph of the original oil painting by Robert Harris, CMG, RCA, formerly in the Railway Committee Room of the Centre Block, Parliament Buildings, Ottawa. It was destroyed by fire on 3rd February, 1916.
The painting is not shown in its entirety. Eight members of the group in the original work were omitted from the stamp for reasons of space and balance of design. The omission was rectified when the subject was again used for the 2-cent stamp of the Confederation issue 1927.