Hello,
Thanks for posting about this. The logged-out version of a Strava activity will include include activity distance, elevation, moving time, pace/speed, calories, relative effort, photos (unless profile is set to followers), map, elevation profile, top achievements, splits, popular segment matches and your effort time, kudos, and comments. It would be necessary to log into Strava to see more activity details.
Keep in mind that what you see will also depend on the privacy settings of the account who's activity you are viewing. Check out this article for full details