The Guardian, a responsible newspaper, merely states:
A Police Scotland spokesman said: “We have been made aware of social media content. We are making inquiries and assessing for criminality.”
The important thing here, imo, is context. We're talking about another football player and we don't know the context of the alleged picture and how it may have been captioned. It could have been a celebratory pic from an after-game dressing room where the subject could have been in a sports bra and shorts for example. There is still nothing, at this stage, to suggest there was anything sexual in the circumstances of the photo itself or any alleged emoji reaction from Griffiths. Note The Guardian doesn't refer to any specific picture, reaction or 'string of texts'. We have only the utterly-unreliable and blatantly-biased Daily Rancid's lurid speculation as to the nature of the 'content' under police review.
If he is guilty of inappropriate, sexual communication with a child then throw the book at him and void his contract. However, at this time, we know only that some content is under review. The club are right to exclude Griffiths while said investigation is pending and they are also right to hold off on making any decision or public comment until the police investigation is complete and the results have been made clear.