Expected Behaviour

Why does it tell me “this” when I am exporting a picture? What could be the reason? I am using Windows 10.

Reproduction Steps

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Your Browser and Device

Operating systemWindows 10
IP address
Javascript enabledYes
Cookies enabledYes
Flash versionNot installed
Java versionNot installed
Websockets supportedYes
WebGL supportedYes
Languagezh-CN
Browser size1486 x 1473
Screen size2160 x 3840
Color depth24 bit