Tom: I have an Apple. I went to the photo with 2 fingers click on it. Click "edit with"  chose Color sync utility. Top RH corner is an icon that looks like 2 rectangles in a rectangle, click it and resize to 144 dpi.
That's what I did anyway. good luck.

Why this was different, I do not know. You can't exceed 500 KB. I did find a way to adjust that, put sure had to look. Don't know why it was different. 

Old Soldier, there are two parts to "size". The 252KB pic is great and it fits on the screen. The 447KB is also good but the size ratio is such that it is too long for the screen. If you control the pixel counts for height and length then the size will take care of itself. The pixel counts on the first image are such that the maximum height could be a few percent less to fit better and on the screen and the length could actually be about 10 percent more and still fit on the screen as long as the height was reduced proportionally. For a rule of thumb 600 to 700 is a good height and 800 to 900 a good width for a horizontal photo. You just have to make sure that it balances out.

You guys got me looking closer at my iPad.
I have always emailed myself photo to resize, if I need a quick picture resized, it auto resized when emailing.  

I don’t know why I had not seen the resize program built into it before.

Couple test photos of different sizes.  One is 800 wide the 1000.

It is actually working very fast for me.
Bob

Just checked and my iPhone 11 works the same as my iPad.
Bob

test 2