Mobile GUI agents can automate smartphone tasks by interacting directly with app interfaces, but how they should communicate with users during execution remains underexplored. Existing systems rely on two extremes: foreground execution, which maximizes transparency but prevents multitasking, and background execution, which supports multitasking but provides little visual awareness. Through iterative formative studies, we found that users prefer a hybrid model with just-in-time visual interaction, but the most effective visualization modality depends on the task. Motivated by this, we present AgentLens, a mobile GUI agent that adaptively uses three visual modalities during human-agent interaction: Full UI, Partial UI, and GenUI. AgentLens extends a standard mobile agent with adaptive communication actions and uses Virtual Display to enable background execution with selective visual overlays. In a controlled study with 21 participants, AgentLens was preferred by 85.7% of participants and achieved the highest usability (1.94 Overall PSSUQ) and adoption-intent (6.43/7).

翻译：移动GUI代理可通过直接操作应用界面来自动化智能手机任务，但它们在执行过程中如何与用户通信仍缺乏充分探索。现有系统依赖两种极端方式：前台执行能最大化透明度但阻碍多任务处理，后台执行虽支持多任务但视觉感知能力薄弱。通过迭代式形成性研究，我们发现用户偏好具有即时视觉交互的混合模式，但最有效的视觉模态取决于具体任务。基于此，我们提出AgentLens——一种在人类-代理交互中自适应使用三种视觉模态（完整UI、部分UI与生成UI）的移动GUI代理。AgentLens通过自适应通信动作扩展标准移动代理，并利用虚拟显示技术实现带选择性视觉叠加的后台执行。在21名参与者参与的对照研究中，85.7%的参与者更倾向选择AgentLens，其可用性（整体PSSUQ评分1.94）与采用意愿（6.43/7）均达最优水平。