JJAG Photography wrote:
I haven't been into ModelMayhem a lot the last five years. I have a handicapped daughter. so it takes a lot of my time. But i've started using MM more. and shooting more. and I've noticed female models posting pictures of them completely nude. but putting hearts, or paint over their exposed body parts. the ones that i'm interested in why, is the ones that have other pictures you can see everything. but then another picture it's blacked out, or blurred. is this a new thing? I know it was done in the past. it just seems it's more common now. I understand maybe the photographer gave them that way to the model. but why?..

For the most part your inquiry seems to be about the mindset of the model, and you're asking in the wrong forum for that. If you want to ask for a model's input, I suggest asking in the Model Colloquy forum and specifying that you're looking for models' responses.

If the last part of the question is "if a photographer gave a model a photo with explicit nudity obscured, why?" then I would posit that if I were asked by a model to give photos with such obfuscation, I would assume it was because on many social media platforms, posting of photos with exposed female nipples and any genitals are prohibited (Instagram/Facebook especially). I would have to assume that if such images were posted where nudity was acceptable, it was because either the model didn't also have unobscured versions to upload, for which there are any number of reasons, including that the model only received upload-resolution versions with the censoring icons in place, or that the model wasn't concerned about which version was uploaded here.

But if you want to know what the model was thinking, ask where the models will be more likely to  see the question.

JJAG Photography wrote:
I haven't been into ModelMayhem a lot the last five years. I have a handicapped daughter. so it takes a lot of my time. But i've started using MM more. and shooting more. and I've noticed female models posting pictures of them completely nude. but putting hearts, or paint over their exposed body parts. the ones that i'm interested in why, is the ones that have other pictures you can see everything. but then another picture it's blacked out, or blurred. is this a new thing? I know it was done in the past. it just seems it's more common now. I understand maybe the photographer gave them that way to the model. but why?..

Because most other social networking sites don't allow such images and most of the world uses those rather than MM.

JJAG Photography wrote:
I haven't been into ModelMayhem a lot the last five years. I have a handicapped daughter. so it takes a lot of my time. But i've started using MM more. and shooting more. and I've noticed female models posting pictures of them completely nude. but putting hearts, or paint over their exposed body parts. the ones that i'm interested in why, is the ones that have other pictures you can see everything. but then another picture it's blacked out, or blurred. is this a new thing? I know it was done in the past. it just seems it's more common now. I understand maybe the photographer gave them that way to the model. but why?..

Instagram.

People post versions of photos that are barely compliant enough to pass Instagram censorship, they also use that same version for other networks because its otherwise too much work