Email attachment images arrive tiny

Suddenly today when I send email attachment of images they arrive in a fraction of the size I am attaching them with my emails (see image showing original image size vs. the one arrived to my Gmail account as a test). I do not know when this started exactly, it's been a couple of weeks since I sent images and I did not change any settings. Checked email settings now and couldn't find where this can be controlled. Why my image attachments changed to small and how do I change this back so original size images? Thank you!

System: MacBook Pro M1 Pro, OS: 15.1.1