Honestly he looks like a standard grey, but maybe that is because he is so filled out.
Lions get their name for being close in color to normal lions but they also have a head that is more circular than a normal glider. Everything about the above glider looks very standard [excluding his weight]
Lions are only referred to as Lion and not Lion Head, their head shape is a very subtle change from the normal glider but it can be noted, what is really striking about them is their coloring which is slightly orange/yellow.
I have seen the picture of your glider and this glider but we really can not judge them without a standard grey next to them because, the photos are low in quality, and the lighting is low in both.
You would think it should be obvious whether or not he is one but I believe camera's and artificial lighting effects the outcome of the pictures and distorts their natural view.