The obvious question is why. Over the past five seasons, Howard has been worth minus-4.5 WAR. He can't run, he can't field and while he can run into a mistake pitch every now and then, he's coming off a season with a .257 OBP. There's obviously no risk on the Braves' part, so even though GM John Coppolella said, "It's just something we thought would be a good option that could possibly help make us better," this may really be nothing more than the Braves extending an option to a longtime veteran and former MVP to let him retire on his own terms.
On the other hand, maybe the Braves think Howard actually can help a terrible bench that includes two light-hitting catchers, Kurt Suzuki and Anthony Recker, plus utility players Jace Peterson, Chase d'Arnaud and Emilio Bonifacio. Buried within his .196/.257/.453 line from last year was a .262/.324/.608 line in the second half, when he mashed 13 home runs in 130 at-bats.
So maybe the Braves view him as a viable pinch-hitting option or a designated hitter in AL parks. Of course, we also have a five-year track record indicating that his second-half surge won't be replicated. We also know that he can't hit lefties at all, which means even his usefulness as a pinch-hitter may be limited. If he's called upon in a tight spot, there's a chance the opposing manager will simply counter with a lefty out of the bullpen, forcing the Braves to burn a bench player or let Howard flail away (he's hit .180 against lefties since 2012 and .128 the past two seasons).
The Braves know all this, which is why Coppolella also added that Howard is a "great makeup guy and is good with young kids." That sounds reasonable -- except the Braves have one of the oldest lineups in the league, with five of the eight regulars 31 or older. Two of the other three starters are Freddie Freeman and Ender Inciarte, who have plenty of big league experience. Four of the five bench guys are 30 or older. So who, exactly, will Howard be helping? I doubt his plan includes spending the summer in Triple-A.
During this rebuilding phase, the Braves' have shown an odd inclination to bring in veterans with low OBPs -- Matt Kemp, Brandon Phillips, Adonis Garcia, Tyler Flowers (although he did have a .357 OBP last year, well above his .302 career mark). For a rebuilding team, it's a strange roster. Adding Howard would be the strangest move of all.