There was a bigger picture of that picture that was comparing the new Kyurem' stats to Reshiram and Zekrom. I have the full picture right here! I'll show you.
Now for discussion of their stats. If Reshiram doesn't have a +Sp.A raising nature and Zekrom doesn't have a Attack raising nature(It looks like they don't) then we can assume that Black Kyurem and White Kyurem's attacking stats are well over Base 150. Unfortunately, we don't know IVs and EVs, so all we can really do is estimate their base stats. From what I can see, it looks like Black Kyurem and White Kyurem could have somewhere between Base 160-180 in Attack and Special Attack, respectively. What do you guys think?