From this book "Deep Learning and Convolutional Neural Networks for Medical Image Computing"
Interest and advances in deep learning are still growing rapidly in
both the computer vision and the medical image processing
communities. In the computer vision community, there is a developingsense that the large ImageNet archive used for training the first
generation of deep learning systems is nearing exhaustion and new,
larger next-generation image databases are needed to take deep
learning to the next level, e.g., the Visual Genome project
Sometimes "developing" means that something is currently underdeveloped and not advanced or mature. People sometimes use it that way when they talk about "developing" nations or economies. But here it just means "growing". So a "developing sense that ... XYZ...." means that the belief in XYZ is growing and becoming more respected as more people are starting to believe that XYZ is true.