Pictures and spoilers presented in 'pictures' tab are prepared to view on PC screens. That's why there are often too big on small smartphone screens. I know there is possibility to double tap to zoom out a view but I think better solution is to add a constant width parameter to images.html in Locus data directory.
.... <img src="7a4a855f-dca6-4b34-9c1e-64d8486e4bb3.jpg">......
->
.... <img src="7a4a855f-dca6-4b34-9c1e-64d8486e4bb3.jpg" width="320">....
where "320" is example phone screen width.
.... <img src="7a4a855f-dca6-4b34-9c1e-64d8486e4bb3.jpg">......
->
.... <img src="7a4a855f-dca6-4b34-9c1e-64d8486e4bb3.jpg" width="320">....
where "320" is example phone screen width.