Now that's more like it.

Note the sandal on her... mechano-ear thing? ...as well as, apparently, on both feet. Does she carry a spare?

She had two pairs, but one fell off the other robo-ear thing.

NWF_Renim said:

She had two pairs, but one fell off the other robo-ear thing.

Either that, or that extra one is someone else's (presumably Tatsuta's, since it's the same style as her own), and that damage came from a catastrophic volleyball accident.