映る and 映す: reflections and screen images
Compare a reflection in a mirror with showing an image on a screen, distinguishing 映る from 写る in photographs.
An object reflected in a mirror
鏡に窓が映っています。 says that a window is reflected in the mirror. With 映る, read うつる, 窓 is the subject and 鏡に where its image appears.
湖に山が映っていました。 says that a mountain was reflected in the lake. The mountain has not moved into the water; its image appears on the surface.
Show an image
画面に地図を映してください。 asks someone to display a map on the screen. 映す, read うつす, marks the displayed map with を.
プロジェクターで壁に映像を映しました。 says that someone projected an image onto a wall using a projector. で marks the device and に the projection surface.
Distinguish photographs from reflections
写真に顔が写っている describes a face captured in a photo; 鏡に顔が映っている describes a face reflected in a mirror. The readings match, but the contexts differ.
画面に何も映りません。 says that nothing appears on the screen. The absence of an image does not identify a faulty part or the cause.
Does 湖に山が映っている mean that the mountain moved into the lake?
Show the answer and why
No. The mountain's image is reflected on the water. Distinguish movement with 移る from a reflected image with 映る.