Images on mobile are blurry

Site URL: https://www.meaganmaher.com

I'm having trouble with my images showing as blurry on mobile. They are sharp on web but for whatever reason, the transition to mobile is messing with the quality. I have formatted them to be the correct size so I'm not sure why they look so bad. Has anyone figured out how to fix this issue? Thanks!

(password for website is: spring)