Because they are both white boxes with large pictures of the product on the front? Well color me outraged!
I think anyone with any eye for design would agree the two boxes are sufficiently different to rule out the possibility that Samsung was trying to pass of as an iPad. (Not to mention the two prominent uses of the Samsung brand on the Tab packaging's front - as opposed to a logo-less shiny black rectangle on the iPad's.)
I honestly don't understand where all these "Galaxy Tab is an iPad clone!" accusations are coming from. Is it a physically similar device? Yes, it is. But there's only so many ways you can design a minimal touch-based tablet. If you made a car that looked suspiciously like mine from the front I'd have a good reason to be pissed off. If you made a wood colored dinner table with 4 legs and a flat surface - probably not so much.
The default screen on Nexus 7 is not mistakable. TouchWiz or Sense are not mistakable. This box shows a tablet configured to look like iOS, which isn't what I or most Android owners do with our Android tablets.