GR translation: in dark confessional

[Mike Jing]

P96.34-35  ... + Katje and Gottfried both kneeling, side by side in dark confessional + ...

What is the meaning of "confessional" here?  The published translation has it as:

2. chiefly  Christianity, RC Church  a small stall, usually enclosed and divided by a screen or curtain, where a priest hears confessions

but it seems wrong to me both grammatically and contextually.  Could it mean some kind of attire suitable for confession?