In my haste earlier I overlooked the fact that 2 different individuals are involved here.
1. The rather bland face pattern and overall pallid appearance (including lack of contrast to tertials, remiges & rectrices), bill pattern and emarginated p6 looks good for Sykes's, although the bill is at the short end (within overlap range of Booted?). However, the pp seems rather long (6 tips showing?) in addition to the rather short tail which Andy has already remarked. It can be difficult judging pp especially when the wing is relaxed, as is the case here and, when it comes to judging tail length, the angle is unhelpful. On balance, I still favour Sykes's, though would like to see more images.
2. The combination of flared suprcilium, bill pattern (unless it's shadow?) + rather short tail would point to Booted but again would need to see more images.
Sykes's/Booted can be a particularly difficult pair to separate in the field and, arguably no easier from images, especially singles. It is worth noting, on occasion, they are inseparable in-the-hand such is the degree of overlap in wing formulae and biometrics in which case a feather sample would be required!
Grahame