When special occasions come during the year, it is a very good opportunity for breaking the routine in your site and get more attention around the theme that everyone is focusing at the moment.
What kills user attention is repeating the same over and over. So why not taking advantage of the special times.
The only issue is if the used icon, graphic or message is not consistent with your theme or is very overused and cliche.
I suggest to use your icons and graphics somewhere around the header or replace it with permanent icons temporarily for Easter time.