I think it is a stamp FROM 1898 (from Canada, obviously) showing the British Empire as it is then, not one from modern times, celebrating the British Empire as it was in 1898.
(It's a 2 cent stamp - in 1963 a US Airmail stamp was 8 cents. Could mail have only gone up 6 cents in 65 years???
1898 Canadian Stamps #85i MNH. Map of British Empire on Mercator Projection