Appears to have a complete eye-ring, pale lores giving an almost bland face, with no real contrasting eye-stripe/super which one might expect from Willow Warbler. Also dark legs, limey green wing panel, limey green rump which as a suite of characters together do not support or endorse Willow Warbler as a candidate imo, add to that an ill defined port primary length, which I believe is visually extended by the starboard wing.
Cheers