It is ironic in that she seems to think that Block thinks the internet is serious business, when he doesn't seem to at all, and she is, in fact, acting much more like the internet is "serious business" than he is right now. Of course, if you want to be really anal about the word "irony" or "ironic," it might not specifically fit the true use of the word. But oh well. Anyhoo...

Wuv, Yer Mom