Steph never really mastered how to disguise her voice, so Laura would be able to recognize her. Once she's put everything away, she purposefully relaxes her posture and steps closer, she's just as curious about Laura and wants to get a better look at her.

"Thanks." She takes it as both a bit of advice, and permission to be in this area. She's not sure if this is Laura's 'territory' but she's used to dealing with Batman so she's kind of made the assumption.

"Why'd you follow me?" It's curiosity rather than an accusation, Steph doesn't think Laura was after her or planning any harm, so now she's just wondering why Laura started following her.