Hmmmmmm interesting interpretation of "portable"
A cannon on a carriage is certainly designed to be portable. Even the big guns on rail cars were/are portable.
The cannons on sailing ships traveled the 7 seas, loaded and ready for action..
And I do agree with you, careful pixel examination of the titanium cannon rendition (observe the shadowing especially) clearly shows this is not an actual picture.
The reflection of the cannon is not a reflection, blow up the "picture" and it's clear that the reflection is an exact duplicate, he did not even bother to mirror image it (ie, the inscription on the muzzle is still right side up) So no, that is definitely not a photo. It's not even a particularly good rendition. And where is the fuse hole? I see a rear sight groove, but no vent hole.
Andre also mentions the first machining, but the trunion clearly shows a casting line.
The OP has also made a statement on the recoil of the piece, but no photographs of the actual alleged firing were offered.
I too would like to see more evidence of the actuality of this piece.
Titanium is about 30-40% lighter than steel, so the recoil would be proportionally increased.