It's a "neat" feature to be able to position photos anywhere in a message, but if enough people don't like it (or don't use it properly. We can disable this option.
Part of the issue is browser dependent. Some browsers appear to automatically "wrap" the row of photos to the next line so you don't have to scroll. Other browsers don't.
Personally, I would prefer people not use the attachment formatting unless there's a good reason.
Thanks,