@Justin_Barrett hits the name on the head: It has to do with the interaction between the browser and the server, coupled with your local settings. Unfortunately, Airtable grabs control of your right mouse key, so you can’t do the usual right-click-and-download-as trick. There are extensions out there that allow you to move that function to another key/mouse combination, though; yhou’ll want to search for one that works with your browser.
Interestingly, on Chrome, at least, if I change the name of the file from ‘image.png’ to ‘image.bin’ and upload it as an attachment, when I click on the resulting URL, it downloads rather than displays. That’s not the interesting part: The interesting part is that the browser parses the incoming file and stores it as ‘image.png’.
Ah-ha! you think. I’ll just create a formula field that wraps my attachment URL with a
SUBSTITUTE() function replacing
'bin'. Alas, 'twas not meant to be: Airtable sees the resulting text as a URL, and it attempts to start the transfer — but then issues a ‘file not found’ error. (Well, actually it’s ‘access denied’ – but it means the same thing.)
Unfortunately, the file display library Airtable uses doesn’t try to identify ‘.bin’ files, so any image uploaded with a ‘.bin’ extension can’t be opened in the browser; instead, it shows as a generic document.
These tests are all performed with a Windows system; conceivably the results might be different from an iOS machine. (Do Apples even use resource forks these days?)