Ah yes, that's true, thanks for mentioning that! I really should have mentioned the reason for suggesting this in the first place, hehe, sorry. I was looking at what setIcon does internally, and it seems it actually uses ImageData on some level, but a lover can only use an Image, which then (I think) gets converted to ImageData. So if there's no technical reason why this isn't possible I thought hey, why not, it would save lovers from having to create an Image they wouldn't otherwise need if they wanted to set the icon to an ImageData or Canvas.
Edit: Actually I guess it's pretty... random... to accept these.