Zoom-in image turns into collage

Hi Everyone,

First off, I just want to say that I am a person who is unfamiliar with computer coding or understand 90% of computer lingo. So I’ll do my best to explain my problem in layman’s terms.

I have a website that was created for me, which all I do is upload new images on it. This is how I updated.

The theme that I’m using is Twenty-Eleven I believe. The issue that I have is in my gallery. I have a page where there are 2 thumbnails with 2 different images. On the same page there is a previewer where you can see the enlarged version of either thumbnail image. This previewer also has a zoom-in function, where you use your mouse to hover over the image and it automatically zooms in.

My issue is that when I upload my new images to this gallery, the preview image is 1) blurry, and when I use my mouse to hover over the image 2) a collage rather than just the zoom-in on the image.

I had someone resize my photos (they were all high resolution and .tif so very big images), to images that would be easily uploaded to the site.

My issue is basically 2 parts.

1) Is the zoom-in issue coming from the file that I uploaded? or
2) Is it my website?

Another thing I should mention is my gallery has other images on there that were previously uploaded last year- and they continue to work fine. It’s just the new additional items that I’m trying to upload that isn’t working.

Any help would be great! Thank you everyone!