The icon is a logo for the Callback Feature. The icon is what appears to be the shape of an old phone. The phone is at an angle with the top of it to the top left. There is a curved arrow that starts at the mouthpiece and points to the top.
This is the Callback icon for Windows 10
. Here we go. Optimized for 32x32 px, these are the simplest icons in the line style. Downloadable formats are PNG and SVG, among others. Icons8 icon pack is unique in providing a huge number of icons designed by the same team of four designers who create the new icons every working day in the same style and with the same quality. Same cool as the Bat Face, huh.