In RDG I found this sentence:
said after a very shy and introverted character smiles; I understand that means something like "So you can smile normally", but I don't understand what nuances adds the construction ば-potential. I tried looking for it on my grammars and on the Internet, and I also tried looking here for "ば potential" and for constructions like that (笑えば笑える, 買えば買える, etc.), but I wasn't able to find anything about this construction.
What do a construction like that mean? How does it differ from 君って普通に笑えるんだ?