That's what I thought- that it might be from
episode 1 when Parn and Deedlit are in the 
Dwarves' Hall with the mural. But when I 
watched the scene, it didn't seem like the
cel was from that part. I can't remember
any other time when she is lighted in blue
like that during the OVA... does anyone have
another guess as to where it might be from?