A workflow which will generate links from placeholder images of any size you want.

A QRcode generator with python-qrcode for Alfred Workflows

Convert an Image to Base 64 Encoding

Google Image search based on image files on your computer

Pastes the URL http://lorempixel.com to your frontmost app so you can add image dimensions and get a placeholder image.

Takes a picture with your iSight, saves it to the desktop as "picture.jpg", and then previews it using Quick Look.

Lossily compress jpg, png and gif files