One thing that was super common on Mastodon / Fediverse prior to this mass migration was adding image descriptions to help be accessible to our many blind and partially sighted users here. Many people won't boost posts without them.
Please consider adding alt text to your images when you can. 
@BlurTheFur I tried this on the iPhone app. But it wasn’t working (🤷🏻‍♂️). Tapping, etc. on the placeholder text didn’t do anything. Likely user error on my part.
@DavidKnuffke @BlurTheFur I had the same problem. Does anyone know how to do this in the app?
@paulmitchell @DavidKnuffke @BlurTheFur I’m trying to figure it out too. No clue.
@DavidKnuffke @paulmitchell @BlurTheFur @SpraklesBooth use Metatext for iOS instead, it’s a better app. Free and accessible, and makes adding alt text easy. Even has text recognition for images with text in them (e.g. signs).
@Viveka @BlurTheFur @SpraklesBooth @paulmitchell I have now downloaded Metatext. And it is much nicer. Many thanks!