Sort of and with minimal GM-tervention. If the DM has a Plus or Pro membership level then there are safe options but if not there is still an option but it would require a fair amount of trust. At it's simplest the player would need to be promoted to co-GM to enable them to upload images (it would go against their quota and be tied to their account, not the GMs), they could then create sheets and set the tokens to be the default and give themselves edit access to the sheets. Once demoted or in 'player' mode the player would then be able to drag and drop the required token from the journal page as per your standard PC token. A more complex but 'safer' version of this would be having the GM create another game to promote the player to GM in and then use the vault (plus sub and above) or transmogrifier (pro sub) to import them into the main game.