So I finished my first creation a few days ago. I built a house, submitted it and got a message back saying I needed to make changes. One of them was:

Screenshots - Far/Small/Thumbnails
Your screenshots are too small. They are either thumbnail versions instead of full-size, are taken from far away, or are otherwise too small. Make sure you upload screenshots big and close enough to see the detail of what you have made. The maximum size for pictures on MTS is 1280x1024 pixels. Minimum Size: 800 pixels wide by 600 high - all of your screenshots should be larger than this, unless you include a thumbnail or other deliberately small pic.
If you make a collage of your images, all required images for your upload must be at least 800x600 individually in the photo collage.
Please see our Screenshot Basics tutorial for further help.

I've had to try and change this about 5 times already.
My screenshots are 1280x1024, I also lowered the file size to be able to fit. I submitted again and I got the same message again saying the screenshots are too small. Can someone please explain what I'm doing wrong? Thank you

Isn't there an option so that you can reply and ask the mod who rejected your upload exactly what's wrong with it? Or a forum you can post and only you can see the thread. I'm sure it is. I'll go on a hunt to find it!

I got this in one of my uploads need changes mails:

Ah! I didn't notice that part. I'll do it now.
Thank you for replying

Glad to help