Small size (half thumb nail) shown in pic 2 comparison with mussel (which itself is small).
No interactions present.
I've never seen an L. c. with so much white, though conchsoc.org comes near. But dubious on significance of the colour diference between plates & girdle. NB many chitons unidentifiable without dismantling the plates, but besides being much the commonest,only it & Tonicella rubra ("orange to pinkish") are "intertidal",& March 19 was almost a neap tide.
Lat/Lng: 51.3821, 1.3144
OS grid ref: TR307699
In eulittoral zone towards lower shore.