Formula for including multiple images in an image field

I can’t figure out how to write a formula to include multiple images in an image field. At least, I can’t figure out the right way to do it.

In my case, I can successfully embed a single image like this:

thisRow.[Icon 1].[Icon Image]

I’ve tried various approaches to concatenate multiple images together, but the only thing I’ve found that displays my images is this:

List(thisRow.[Icon 1].[Icon Image],thisRow.[Icon 2].[Icon Image]) etc.

But this isn’t the correct way, as I get an ‘invalid values for image attachment’ error, and the images are displayed small - I think it’s switching it to a text field. Ultimately this is workable, as my images are displaying, but it’s not the ideal approach and I’d love to know the right way here.