I was really pleased to find out about this google extension, as (for work) I use Microsoft 'screen snip' tool all the time unfortunately, although the google extension feels similar in the 'capture' of the part of the screen you wish to embed to your gMail, it never completes the task by adding it in it just 'hangs' ( i waited for over 5 minutes before cancelling the instruction and doing it the old way of making a 'paint' copy and attaching it as a ".gif" file)
The 'Gmail Screenshot by cloudHQ' plugin falls under the 'Productivity Tools' category and offers features such as Screenshot Capture, Annotation Tools, Collaboration Tools, and Email Integration
It allows users to take a screenshot, annotate it, and send it directly from Gmail
The plugin also facilitates sending design feedback by quickly adding comments on a screenshot of the image and sending it for revision