Image size preventing indexing on BING?

Imagine two domains named for a non-celebrity someone FirstMiddleLast-dot-com and FirstMiddleLast-dot-org. The last name is uncommon. Let's call him George Ringo Wyckoff. The two domains, GeorgeRingoWyckoff .com and .org versions, built with WordPress, are ranked #1 and #2 in the regular SERPs on Bing. Each website is filled with dozens of unique different actual images of "George" and each image has descriptive unique alt tags related to "George". The images aren't appearing in Bing searches for George Ringo Wyckoff or, without his middle name, George Wyckoff.

How can I expedite getting images indexed on BING so that when one clicks the Images tab after searching, there are many of the new actual pictures of George?

Is image size a factor? They're big, many over 2000 pixels on the long side. Should I downsize the images and add links on the pages to optional larger versions? Provide multiple versions of the images from thumbnail to huge?

The dot-com site is on the first page of Google SERPs and 3 of the 6 thumbnail photos at the top of the SERPs are from it. I'd eventually like my images to occupy all 6 thumbnails. The dot-org is high on the second page of Google SERPs, so something is right. On the images listing for Google, there are many images, but far from all, from my two sites. There are many images of people who have nothing to do with "George", but it would seem that a portfolio of different actual portraits of "George" SHOULD be more prominently ranked.

There's nothing wrong with really large images on a page. There could be many other reasons these images are not ranking.

What have you done with the EXIF, that is the exchangeable image file format?

What other type of written content is on the page? Including a full paragraph or longer description for every photograph (every page) could be relevant for your optimization purposes.

Have you tweaked the name of the images?

File names and alt tags are tweaked and not spammy. I have excellent saturation in Google images, like 50% of the top 60 images. Using site:domainname.com on Bing I see that 16 pages are indexed, but Bing Webmaster Tools says 40+ pages have been spidered. Just no images are appearing on Bing.

Not much body text. No outside links. Working on onpage optimization before looking toward offpage. The onpage clearly makes Google happy.

Sorry for the delayed response. I was out of town.