There are several ways to allow a client to see all of the images from any event.
1) You can download all images to your Dropbox account and share that link
2) You can download all images to your Google Drive account and share that link
3) You can set up an RSS Feed
4) You can set up a public Facebook album
5) You can give them admin access to your account (not recommended, but easily done). They could log in and just browse the images through the Media Search screen.
6) You can pay us to build a custom gallery ($950 to $2,500 depending on the customizations)
7) But, the easiest way is to just give them a link to a gallery that shows all images from any single campaign. This is included in your package. You can add a custom banner at the top of each gallery page. When they click on any thumbnail in the gallery, it expands to full view (it will ask for contact info, if none has been associated with the image yet). Each campaign has its own gallery. Here's a good 'how-to' article