In both photos, the supercilium appears to reach the bill base, pointing away from Arctic.
在这两张照片中,眉斑看来皆往前延伸到嘴喙的基部,这点便和极北柳莺不同。
The majority of Arctics to my eye seem to have ochre-toned legs, and the supercilium does not reach the bill (which can be very hard to judge in the field).
在我看来大多数的极北柳莺似乎有黄土色的脚,且眉线没有到达喙。