Fortunately for you my main internet connection is down. I'm being forced to use the hotspot on my phone, which is slow enough that your problem jumped out and hit me in the face.
Your pictures are too big. They download at a crawl.
So, I looked at your source, just to be sure, and sure enough you are using full sized pictures as thumbnails. Constraining their dimensions in html does nothing to reduce the actual size of the picture being downloaded. It just displays smaller.
The reason the iPad is not displaying the pictures is that it is running out of RAM to hold the page. It displays as much as it can, and then substitutes place holders for the rest.
What you need to do is make thumbnails of all the pictures on your main page. Take them into a photo editing program and reduce them to the same sizes you constrained them too in the html. I'm assuming you are using the full versions of the pictures elsewhere on the site. So be careful not to replace the originals with the thumbnails.
What I would do is create each thumbnail and just append something like _thmb to the file name. So picture.jpg would become picture_thmb.jpg.
Save them in the same folder that the original pictures are in.
Then go back to your html and edit the main page by replacing all the references to the original pictures with the thumbnails. It will be easy. All you have to do is add the _thmb to each file name. You can probably do away with the size constraint tags too, but it shouldn't hurt to leave them either.
I am almost certain this is your problem, and that this will fix it. If it doesn't, please let me know so I can make another crazy guess.