Slow Product Variant Image Loading?

I have a multi vendor store in development and I am adding vendors products. My server is a 24 core dedicated server with 32GB of ram. Its running 4.3.7, with php7, opcache and apcu. The store in general is blazing fast. All of my products that have variants with images tied to them load extremely fast but I have one product that has 43 different color options and it is very slow to load each new options image when its selected. Is this a bug? I don't see why a product with 43 options would load slower than a product with 20 with my servers settings and power.

Here is a link to the product with slow option loading.

http://www.anglers-marketplace.com/salmon-flashers-vip-outdoors.html

Here is another product with less options and faster loading.

http://www.anglers-marketplace.com/uv-steelhead-yarn-steelhead-stalkers.html

Let me know what might be causing this and if I need to report a bug? Thanks.

First thing id say is the large image on the slow product is 73 kb

http://www.anglers-marketplace.com/images/detailed/2/1-9_zft6-7v.jpg

this can be reduced to 18kb by optimising.

Maybe all images on this product have the same problem, which will slow down load times.

The fast loading product images only seem to be 50kb or 40kb in size

I have other products with images as large as 120 kb and they load as fast as any others. There is an actual delay before the image is even stared to be loaded. The larger images might load slower but they all start their initial load at the same time. In the product with a lot of color options there is a one second delay before the picture starts its initial load.

There is on average a 1.45 second delay according to firebug before image starts loading. All other products and their option images have a delay of 90ms on average before image starts loading. There is definitely something going on in the background. I also noticed that I could only upload about 30 product option images at a time. If I loaded all 43 option color images when making the product the screen would reload with about 10 product option images not loaded and I would have to re upload those.

I believe I figured it out. I went through and imported all pictures that had a delay into photoshop and exported them to JPEG (same file type) and optimized them. All are loading fast. The images must have had an issue when they were encoded in the past.