The stretched-out fist means "Check!" an encouragement. Welcome between friends or gesture of agreement. Can also be interpreted as a threatening punch.
The oncoming fist: Medium-light Skin Tone emoji was introduced in 2010 and released as part of the Unicode 11.0 standard. This emoji can be found under the people and body
category. Because the oncoming fist: Medium-light Skin Tone emoji has been around for quite some time, it should display correctly in the majority of operating systems.