Video thumbnail in iMessage small

Hi Westfc10.

When that setting is enabled, only smaller, low-resolution versions of photos and videos are kept on the iPhone itself, with the full resolution versions being stored in iCloud. What may be happening is that, when your wife sends a message with a video, the smaller version is being sent rather than the full-resolution one.

Depending on the amount of storage available on her device, testing for this may be tricky. What you would want to do would be to disable that option and then (after the sync is complete which would put full-resolution versions back on the device) try sending a video again.

If you are not able to turn this feature off due to lack of space on your wife's device or if doing so does not resolve the issue, you'll want to reach out directly to Apple Support for additional options.

Contact Apple for support and service

Cheers.

Hello Westfc10 and welcome to Apple Support Communities. It appears you are having some difficulty with video attachments to group messages.

Send a group message on your iPhone, iPad, or iPod touch

It's important to keep in mind that, with a group message, unless all of the members of the group are using Apple devices, the format defaults to SMS or MMS for media messages. And both SMS and MMS are totally controlled by the carrier. The Messages app simply serves as a client to display data.

Cheers.

Hi Westfc10.

Do all members of the group have iMessages enabled? A small portion of iPhone users seem to disable that in order to force the device to use SMS. If SMS is being forced, the outcome will be the same as if one or more people in the group were on Android devices.

Cheers.

Hi Westfc10.

That is helpful info. Is your wife using iCloud Photos? If so, is the Optimize iPhone Storage setting enabled at Settings > Photos?

Cheers.