e.g if you use IMGUR as host for your image, simple visit https://imgur.com, upload your image on there straight from your PC files and when the image has uploaded, right click on the image and copy the "image location URL", usually ending in ".jpg or .png" and paste it into the body of your post on https://steemgigs.org and you will now notice that the image loads up during "post preview" and your post will now publish successfully.
Steps on participating this wonderful flat form..:)