Automatic image resize on Mac browser?

Hi,

I’m a student in a business school and I’m working to understand how WordPress works in order to modernize our student newspaper website. I’m pretty new to this, so I’m sorry if I ask a question with an obvious answer.

I’m learning a lot by searching and reading online, but there one answer that I can’t seem to find. I’ve noticed that when I insert a media in a post, a picture for instance, I can’t resize it proprely when I’m on my Mac. Actually, I select the size in WordPress when I import it (small for example), or sometimes I resize it manually by dragging the picture corner in the post. The problem is when I preview the final article, either in Chrome or Safari, I notice that my browser takes the resized picture and puts it bigger, as if it saw the original size and bypassed the size that I chose in WordPress.

When seeing the exact same post, but on Chrome for Windows, the picture size is fine.

The weird thing is that I can see, when I preview the post on my Mac, the resized picture; it lasts for like 1/4th of a second, and then it becomes bigger. The only thing I could do is to put it very very small, so when my Mac resizes it, the image has a correct size. Obviously, if I do that, all the Windows users then see it as a very small image. Or, if I resize the image before importing it, it’s okay in both Windows and Macs, but doing this for every picture is a hassle and I’m sure there’s an explanation and a solution to this.

I can’t find anything on this problem online (perhaps I didn’t use the right keywords?), so if that rings a bell to anyone here, I would really appreciate some insights from you.

Thanks a lot!