No interactions present.
Did you have any other views? The brownish rear cheeks and suggestion of a pale spot on the beak at the base are quite Marshy...
My Flickr photos...
The visible features in the photo are more suggestive of Marsh Tit than Willow in my opinion.
The hide log at Potteric Carr indicated that the Willow Tit numbers are being monitored at this feeding station. No mention in any of the recent reports of Marsh Tit.
I'd want to see its back AND hear it call before I was certain. I suspect marsh tits occur in Doncaster as well as willow tits.
I agree with Bob - we need more here to definitely split these confusion species
Lat/Lng: 53.4964, -1.1053
OS grid ref: SE594003