When posting positive things promptly*, I think it first makes sense to post positive things from that day (for reason 6**), and then from previous days (that week, or month), in pure date-time order (oldest to newest), regardless of subject (topic) or type of post (e.g. text note vs. photo).
Subject-focused or clustered may make it easier to think/write about all posts for one topic at once (less context switching). However sometimes you don’t know the subject(s) of a post until you’ve actually written it, which means you have to finish at least drafts for posts before you can actually successfully categorize and cluster them, which seems like a lot more work (finishing all drafts before posting one) than just finishing/publishing one post at a time.
Using the date-time (of when that positive thing happened that you’re posting about), has the following advantages over clustering by subject:
* easier to get started: because "date" has an objective (don’t need to think about it) absolute answer that makes it easy to sort your drafts and just start posting them in date order (oldest first within some reasonable timeframe like, in the past week, or in the past month).
* easier to post incrementally, and pause / resume posting: since your "index" is linear (time), you can choose a date / point in time to pause, and later pick-up at whatever date you left-off, no need to think about what subjects did you already posted and what subjects are remaining.
Another consideration for publishing older posts is whether to post different types of posts before others, like text notes vs. photos vs. longer blog posts, or just interleave different post types all by date.
If one type of content had a particular workflow, like editing photos, it could make sense to cluster publishing those. However even photos have captions to write which are similar enough to text notes. Blog posts often open with a featured photo. It almost seems like more work to try to distinguish different types (as an author), than just post in date order, and add aspects to the content, text, photo(s), as they make sense for the post. Publishing them all in date-time order seems the simplest approach.