The objective test is comparable to the English law doctrine that ‘justice must not only be done: it must also be seen to be done.’ In this context, the Court emphasizes the importance of ‘appearances’. (…)
In applying the objective test, the opinion of the party to the case who is alleging partiality is „important but not decisive” (nota de subsol 810: Hauschildt v Denmark, para. 48. See also Vardanyan and Nanushyan v Armenia hudoc (2016) para 82 (judge’s language implied that a refusal to agree to a friendly settlement might affect the outcome of the trial: violation).
D. J. Harris, M. O’Boyle, E. P. Bates, C. M. Buckley
(Law of the European Convention on Human Rights, Oxford University Press, august 2018, la p. 452)