Final answer:
Images may not show in iPhone emails due to disabled 'Load Remote Images' in Mail settings, poor internet connection, or an outdated iOS. Enabling image loading, ensuring a stable connection, or updating the iOS could solve the issue.
Step-by-step explanation:
Images not showing in emails on an iPhone can be caused by a number of factors. One common reason is that the Mail app settings may have 'Load Remote Images' disabled. To check if this is the case, go to Settings → Mail, and make sure that the 'Load Remote Images' option is turned on. If it's turned off, the Mail app won't display images in an effort to save data or enhance privacy.
Another possible reason can be a weak or unstable internet connection. Images require additional data to download; if the connection is poor, the images may not load properly. It's also worth checking if there is an iOS update available, as sometimes older versions of the iOS software can have issues rendering images in emails.
Finally, if you're having issues with a specific email account, you could try removing the account and re-adding it to your phone. This can sometimes resolve synchronizing issues that may prevent images from displaying.