It's a loveseat

It only looks like a colon from above.  Source unknown (emailed to me).

A tip of the blogging hat to reader Drabkikker, who found the source.  And I learn some new terminology:

A loveseat can be one of two styles of two-seat chair.

One form – also known as "British two-seaters" – is essentially synonymous with "two-seat couch". It typically has two upholstered seats.

Another form, variously also known as a tête-à-tête, courting bench, kissing bench, gossip's chair, or conversation bench, is any form of two-seat furniture where the two seats are arranged in an S shape, so that two persons can converse while looking at each other and being within arm's reach, while at the same time typically retaining a modest barrier between them.