I thought perhaps they were imprints of the same things but it looks like they're entirely different start-ups since they are from two different YC seasons.
Both Picwing and Picplum send printed photos to recipients on a monthly or bimonthly basis.
Why not? Isn't competition supposed to be a good thing? Also: if you're convinced an idea is going to be big, why not bet on a few companies at the same time? This is not a horse -race.
An alternative answer is that PG, et al have said time and time again that they invest in people not technology. The partners are probably expecting one (or both) of the start-ups to change dramatically down the road
How is competition "sub"-ethical? Competition drives innovation. VC's say it all the time, the IDEA is worthless without excellent implementation. I find it perfectly admirable that a VC would invest in two companies that have the same idea. It helps the VC feel more comfortable with their investment and adds enough competition that the two (or more) companies will have to do their extreme best to come out on top. The VC wins, the best company wins and the customer wins. Sounds like something Apple might consider unethical, but it's really not, it's competition.
Aren't these the same company, with two different branded services? Didn't Picplum acquire Picwing some ways back?
Also, Picwing didn't start as an online photo sharing service. It was, if I'm remembering right, a hardware product. The service there now was a fallback for them.