1200RC
The calipers in these rear brakes are single piston types. The piston pushes the pad onto the disc on one side only. Once this is in contact with the disc, it pushes the whole caliper across to drag the other pad onto the other side of the disc.

The caliper mounting is firmly fixed, but the caliper itself rides on two large pins that allow it to move lateraly. In normal use, it moves only a few thou. with each brake application. If the disc is warped, it moves quite a bit as it wobles side to side with the disc runout. Over time, the caliper migrates across by the amount that the fixed pad wears. When replacing the pads, it is necessary to not only push the piston in, but to push the caliper across to provide room for the new pad on the fixed [non piston] side.
The rubber hoses allow the caliper to move about all that it needs to without problems, which is why the factory put them there.

Bleeder niples usualy go on the high side as air rises to the top in a liquid, & the purpose of the bleeder niple is to allow ALL the air to be purged from the system.