I’m trying to think what makes it ok / not ok to pull out a phone / laptop:
- Paid vs. free (seems more ok if you or your neighbor didn’t pay to be there)
- Perceived as entertainment vs. perceived as work / academic / boring (totally subjective)
- Level of appreciation (are there connoisseurs around? i.e. at an opera — are you intruding on others experience? Again could apply to a range of experiences)
- Quiet vs. loud (Vivaldi concert [not ok] vs. Green Day concert [ok] vs. presentation about closet hinges [ok] vs. movie about closet hinges [not ok])
- A live person vs. recorded materials
Conclusion: phone / laptop etiquette is complex and arbitrary.