I think sometimes there is a bit of delay before new records have been fully uploaded to iNat’s database and can then be made available for access from another device. I don’t upload much from my cell phone, but very occasionally I have done what you describe and it seems that the observation is created/saved before all the accompanying data – such as media – is finished uploading so it displays as “casual” temporarily.
“Casual” (the German translators opted to call this “hobby”) is not identical to “captive/cultivated”. It means that an observation does not meet the minimum requirements considered necessary for it to be verified and used for research purposes. Thus, an observation may be casual for any number of reasons – being marked as “not wild” is one reason, but it can also be casual because of missing data (no date or location) or because there is no media.