Yes, Canada Party Leaders Can Be Photographed Inside Polling Stations
You can't take a pic inside your polling station. But there are different rules for media pools.

Wondering how Canada party leaders can share photos of themselves inside their Elections Canada polling stations but you can't? The answer is media pools.
Elections Canada allows members of the media to apply to participate in pools (i.e. a few designated individuals taking pics that can be used more widely) specifically to obtain photos of registered party leaders in their polling stations.
The federal election agency confirmed to Narcity that there's no rule that forbids a party leader's photographer from participating in a pool.
Liberal leader Justin Trudeau and Conservative leader Erin O'Toole both shared photos of themselves casting their votes on Monday.
Elections Canada does not allow other voters and candidate representatives to take photos inside polling stations, however.