Interesting had a check on the name but can't find a Restrepia virolin. However there is a town called Virolin in Colombia. So I'd assume it's the location which I often consider more important as the name.
Restrepia's are one of the more difficult generat to identify as their is no good literature available. Luer's key to the genus is completly outdated and not very accurate.
By just looking at the picture I'd gues Restrepia contorta. But this is with a huge question mark as I have no idea on the size.
Rob, my first thought was Restrepia contorta. I have one open just now with 3 flowers, so it may be on my mind... but it imediately made me think of mine and I then saw the name and thought "no, must be something similar"... but I was assuming a correct name
As you said, flower size is difficult to judge in this picture though.