No, not really.

Imagine the user wants to use that package also!
Putting a dependeny and then remove all that stuff later (what about postinst/prerm and so on?) is not a good choice, especially for packages provided by someone else.

And btw if "my" icons are installed first, then the other package will not install with the same error.

--edit
Did only see sifos reply.
Estel you are absolutely right and this is how I handled situation. But, (even it is only 36k) I am not satisfied with that. And icons go to /usr/share, which is not optified, right?
Just wanted to keep rootFS clean.....