OBS: First of all I believe that you have mistaken the title of the question, because you spoke of <figure>, but in the code you put <picture>, way, your problem is with the order of tags...
Your problem is simple, when using min-width the greatest value always has to come first
First 650px and then 490px, if the value of 490px will overwrite everything that comes after
<source media="(min-width: 650px)" srcset="http://placecage.com/300/100" />
<source media="(min-width: 490px)" srcset="http://placecage.com/200/100" />

Follow the image code above
<picture>
<source media="(min-width: 650px)" srcset="http://placecage.com/300/100" />
<source media="(min-width: 490px)" srcset="http://placecage.com/200/100" />
<img src="http://placecage.com/100/100" />
</picture>
The code you put down doesn’t even have that tag
– Costamilam