The icon is a picture of the logo for Field. The icon is what appears to be a farmers field. The icon also has a sun at the top left. The icon has several lines on it, implying that it is a field for crops.
This is a Field icon. We've made it in iOS style
, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 13,700 icons, all in the same style and quality.