@nushin It's probably because you're new in the forums, which is a common thing.
But you don't need to upload images here, there are plenty of online image upload services you can use.
Choose one service, upload your images and post the links here. And actually, this forum will tell you that you can only post one link, which means that only one URL will be linked, the other URLs will just be text, which is fine, all we do is Copy + Paste the URL in our browsers.
Choose your image upload service: http://lmgtfy.com/?q=free+image+upload
Also, you don't necessarily have to share the designs in case there are any concerns from your company regarding posting private information.
But what you can do is share wireframes of the solution rather than designs.
Hope that helps.