Greetings. When I uploaded a photo in portrait mode, it doesn’t appear completely when viewed on my computer using the Mapillary desktop application:
But when uploading a photo in landscape mode, it appears in full in the Mapillary desktop viewer:
Where would the problem be: in the image resolution or in the Mapillary viewer?
Tks.
The problem is in you. You are not supposed to do portrait.
@filipc you also could be nicer, and say “Mapillary wasn’t built for portair photos but only for landscape” or, if you want to explain better
“Mapillary was built for landscape imagery for helping OSM, Here WeGo and picking up street signs/objects for the AI!”
He did not even say “Thank You” for my effort. 
Thank you for the information that portrait photos should not be used. I was unaware of this and I don’t recall seeing any recommendation about it on Mapillary. I may have missed it.
Strangely, the landscape image also doesn’t appear completely full screen. It seems that the images need to have a certain aspect ratio to appear correctly in the Mapillary viewer.
You can upload portrait orientated imagery and it is properly supported but no sane person wants to use it for mapping. Nobody wants to view landscapes through a coin slot shaped peephole. It is like the terms say; portrait orientation is for portraits, landscape orientation is for landscapes. The Mapillary mobile apps have been consciously designed to let users capture landscape orientated images only.
There is nothing wrong with the viewer. The viewer fits an image to the viewport’s width, which sometimes may be the full width of the screen. Why? Because images come in all kinds of shapes, sizes, projections, and aspect ratios, with 4:3, 16:9, and 3:2 (and 2:1 with 360° imagery) being the most common aspect ratios used for mapping. Nobody wants to waste viewport pixel estate, that is, have black bars. Images that do not match a screen’s aspect ratio can be panned when viewed.