The default setting here on Atlas is large @keithkelly. Same on my community.
As there's no setting in Admin/Features/Images I suspect it might be something you need to ask the support team to change if your community has a different default.
BTW, we were also able to ask support to increase the maximum file size that people can share - we increased it as members were getting frustrated that they could not upload images from their phones now that phones offer such high-res (large size) image files.
Here's a photo of a backyard putting green built by one of our community members. I uploaded it without changing the default settings...
Jason
