Screenshots

”They arrive” by what medium - MMS Message, email attachment, AirDrop, or something else?

When attaching or inserting an image, the file selection dialogue normally has an option to select different sizes - and displays the associated file size in KB or MB.

When attaching an image to an email, having attached the image, you’ll see the current attachment size in KB/MB; simply touch the file-size to reveal the attachment size dialogue - and select the image size from the available choices:

I hope this information and guidance successfully resolves your difficulties.

You’re very welcome. I’m delighted that the guidance was helpful.