Bird Identification: CLOSED: Possibly warbler or vireo?, 2 by MartyJo

MartyJo wrote:
I friend sent these pictures hoping for an ID. Unfortunately they're quite small and not very sharp. But since you are quite sharp, I'm hoping someone can help. We are in Iowa - it may be migratory, but you can rule out birds that are seen only on the coasts or in the southwest. The orange helps estimate size and may give other clues. The third image is probably the best. I don't see any wing bars, but that may be the fault of the photo.
Thanks!