@Alice, thanks for inspiring me to suggest a feature! I don’t know if this one exists anywhere else.
Idea name: Let users selectively reveal, always show, always hide, or stylize individual messages based on an optional category specified by the message author.
Description: Message authors may not be sure that everyone will want to read their message immediately, or even at all. This could apply to specific types of humor, content that reveals secrets about movies and other mainstream media (spoilers), content that could be considered to be adult/provocative (NSFW: “not safe for work”), stylized text expressing an action, and more.
Use case: As a message author, I want the option to categorize individual messages for other users to selectively reveal based on their category and context. As a message recipient, I want the option to selectively reveal messages by clicking/tapping them… plus the option to choose message categories that I never want to see.
Target user: Any user wanting to share content that others may not want to view immediately (nudity, spoilers, etc.) or might never want to see, plus any user wanting to use Status without concern for nearby people viewing their screen.
Why this is important: This potentially allows Status to be more user-friendly, as it provides an extra layer of customizability for users who may be using the app in professional environments.
Any other comments:
While this could potentially sound complex, I believe that it can just be implemented on the delivery side as additional metadata that is optionally appended to any message content. On the client side, the client would check for the metadata before rendering the message, and show/mask/hide as per client settings.
This could potentially be specified while a new message is being composed, as a click/tap menu icon in the text entry field (perhaps integrating with the sticker icon) and/or by using commands preceded with a slash. Content tagged as a spoiler or NSFW could be masked with its category name and require an extra click/tap. Content tagged as an emote could simply be stylized. Examples:
/nsfw moms-lightsaber.jpg
/spoiler snape-kills-dumbledore.jpg
/emote picked the wrong week to quit amphetamines.
Sleepy Exhausted Sloth picked the wrong week to quit amphetamines.
Sorry about the images. 
Users could also potentially customize an option in their preferences (one per category) to hide all content for each individual category, always show it, or reveal it after a click/tap. The “reveal on click/tap” option should probably not exist for emotes.
This also presents SNT use cases if users can create their own content categories. Feedback welcome.
If you think this is a great idea and know how to implement it, consider posting a project proposal on Assemble. If you love this idea, hit the Vote button.
My vision for this is to allow users to get creative with reply masking and formatting in a useful way… like even creating a “guess this image” category where images could be blurred or pixelated to the preferences of the author, “guess the number/word” with a caption of something like “1-100” or “another word for automobile”, adding custom descriptions for the hidden content, making the text color the same as the background color, or any number of creative options that make sense. My hope is for people to make new social connections through creative options that don’t clutter the interface, and encourage unexpected engagement. 