Those are all available images. And note that, available images from poky and meta-fsl-arm only. As you may imagine, several other layers can be included, and any new layer can provide new images.
If you look line by line, you can see that some of that files are not images, for example u-boot-mkimage_2011.06.bb but you got the message.
Yocto Project (and meta-fsl-demos) provides some "pre baked" images. In my point of view, those images are not to be used on your product. They are examples and quick starting points.
When you desire a pie, you can go to supermarket and buy a frozen chocolate pie. But when you´re developing a pie to be the Apple Salted Caramel with Dark Chocolate Cinnamon Topping you need to decide every piece of this pie. What is the base, which type of apple to use. How much salt on caramel. This is your product, your pie, not a frozen standard pie.
I know the analogy is kind of dumb. But it´s important to understand that the "pre baked" images provided by Yocto Project, or meta-fsl-demos are not supposed to become a product image! You can (and maybe should) base your image on some of those images, but they are not good enough to your product.
I highly recommend you to have your own image file.
A small image just capable of allowing a device to boot.
when I need to add something like ssh/dropbear or evtest or usb utils. I always configure this on local.conf to add the desired package.
A console-only image that fully supports the target device hardware.
when I need to test X11 accelerated by GPU, or I need to have X11 for any test.
A very basic X11 image with a terminal
when I debug directfb GPU support
An image that uses DirectFB instead of X11.
when I debug Wayland GPU support
A very basic Wayland image with a terminal
when I need to test VPU with and without gstreamer.
when I need to have QT, or I want to build everything altogether. Although I´ve been preferring the smaller images instead.
To have the crosscompiler installed on my machine to manually build u-boot and kernel, when I´m changing it
Meta package for building a installable toolchain
All those images DO NOT include -dev packages or native build. If you want it you MUST configure your local.conf.
Although, you can find special images that provides the header files or the native compiler.
The images with -dev sufix include the header files (and development files) from all packages. For example: core-image-minimal-dev (A small image just capable of allowing a device to boot and is suitable for development work.)
The images with -sdk sufix include the native build tools. For example core-image-sato-sdk (Image with Sato support that includes everything within core-image-sato plus meta-toolchain, development headers and libraries to form a standalone SDK.)