Modern Vespa

I think BB code allows a user to specify height and width in IMG tags, but it doesn't seem to work on MV... am I missing something?

I know I could resize the actual images beforehand. But I was hoping there's a way to change the display size, without having to touch the images themselves.

All BBCode implementations are not the same. Heck, BBCode isn't really even a spec (though there are undoubtedly some people who pretend it is) -- it's a style, a general pattern.

MV (and the underlying phpBB2) has never supported sizes on IMG tags. IMHO, it would be a terrible idea, as screen sizes vary wildly and specifying a hard image size would break the layout for some subset of users.