I have seen (h/t Harel13) it written that, when one says Birchat Hachama, one should bow to the side.
I recall hearing as a boy (2 Birchat Hachama cycles ago) that this was to avoid the appearance of bowing to the sun, which others might misunderstand as worshiping OF the sun.
-- another source which quotes the Chida among others https://www.hidabroot.org/article/238621
Does this same concern apply whenever one davens outside and says aleinu?
*might this also apply to any other bowing done while davening silently, as an outsider would not know what is being said and might misconstrue** the behavior for sun-worship?
**if the fear is others misunderstanding the bowing as worshiping the celestial object, would one change the bowing during Kiddush Levana for the same reason? (h/t Sam)