images is a poor tag name, not only because it does not define any specific task or software, but also because it has more than one distinct meaning, especially in our scope. A brief survey shows that this tag is being used for questions about images that are not pictures of stuff, for example
- Mount single partition from image of entire disk (device)
- What software can be used to create a restorable drive image?
- How can I remove old linux-images when installing new kernel updates?
It seems to me that those three posts (there are more examples similar to each of them) do not benefit from an image tag and the "image" aspects of them are sufficiently defined by tags like backup and kernel. We also have a tag disk-image which would be applicable to the first two.
There are currently 476 posts with this tag, which means a long process to remove it by editing. The majority of the questions are about image processing or specific software as you suggested, and some can simply be tagged software-recommendations, but some of them are about converting non-images to images (there is a tag convert but that is probably at least as problematic as images), or about viewing or saving or identifying or organising images. image-processing may not be appropriate for all of them. There is a tag photo-management which may be more suitable for some. Careful work is needed to apply specific software tags where appropriate.
pictures is probably less ambiguous, but similarly unnecessary and vague in failing to define a specific task or program.
Both should be carefully removed, imho.
We also have a tag photo which doesn't seem useful...