The line above the left ear thresholds is likely meant to be bone conduction. The triangles, however, are suspicious because masked left AC thresholds are supposed to be squares (masked right AC thresholds are triangles). That being said, the code/legend on the right side of the page seems to defend it, but it is indeed awkward from a clinical communication standpoint…"7"s for masked bone conduction?
As far as only measuring bone conduction on the left, I have heard of testers using a shortcut where they test the poorer hearing ear and hope the unmasked threshold matches the right AC threshold so they can justify not measuring the better hearing ear.
Anyway, the biggest fitting consideration regarding the left ear is the type of hearing loss i.e. conductive versus sensorineural versus mixed. The more conductive a hearing loss is, the less cochlear recruitment you will be sensitive to, and the less compression you will need. However, your word recognition score on the left is pretty poor, which is not common with a conductive hearing loss. Without having your hearing retested, I bet your left ear is sensorineural. If you don’t input bone conduction thresholds, I think Target assumes the hearing loss is sensorineural.
EDIT after reading @Um_bongo 's reply, if masking is suspect at all it is not unlikely that even the left AC thresholds are suspect.