> Requiring a second app to do it (posting a link) isn’t nearly as good a UX as simply pasting in pictures.
But what about the UX of other people in the channel? Someone posts an image and the previous text is moved off screen. Now they have to scroll up to read what they were just reading. What about the case where someone posts an animated gif which becomes a distraction that requires you to stop the animation or hide it? What about the case where multiple animated images are posted which forces your client to use a lot of CPU resources to render them[1]?
That may be true for personal use, but not necessarily true for business related use. That's because the former case is limited to users who want to use the product precisely because of its features. In the latter case, users are required to use the product as part of their job. Given that, the ideal case would be to not introduce features that lead to a negative user experience.
The same people who use smartphone IM apps in their free time are using corporate IM clients at work. I can't see why business users would be any different. I expect my app at work to be able to do what my at-home IM client does. It could even be the same one.
> features that lead to a negative user experience.
Any feature can be a negative user experience. There is only one way to see what a majority of users are "expecting" and that is to open the mainstream IM apps in default configuration. The worst case of poor user experience is breaking the expectation that it works exactly like that.
But what about the UX of other people in the channel? Someone posts an image and the previous text is moved off screen. Now they have to scroll up to read what they were just reading. What about the case where someone posts an animated gif which becomes a distraction that requires you to stop the animation or hide it? What about the case where multiple animated images are posted which forces your client to use a lot of CPU resources to render them[1]?
[1] https://mobile.twitter.com/slackhq/status/879755518843252736