We have 2 requests for future versions (if this doesn't already exist - but to my knowledge it doesn't)...
1. Print option for calendar - which would provide a great print out for marketing purposes - current normal printing produces 3 pages that are not format enough to be able to use it..
2. Image enlargement on the calendar - again - this artwork is what sells the event - so being able to enlarge it would help bring more pupils to class.
We'll consider these items... but to address #2... just making sure that you ARE aware that you control the size of the image that shows in the calendar. This is set in configuration on the Calendar tab.
I'm assuming you know that are you are just looking for the ability to display the image larger on a click or hover.
Now, there is also a popup that shows when you hover on a calendar item that CAN include the image also. This will show the image using the size as set for the event listing view. So you could enable that popup and enable the display of the image in the popup... then set the desired size for the popup (configuration -> event listing tab). Hope that helps!