Should be obtained higher resolution. The way to obtain it: First, you should check the higher level is there a tag <a>, if it is then check the @href. If it exists then check if the href has and "/img/" part. Then replace ".html" to "" and "/html" to "" and you will get an image in higher resolution. Example of this image in higher resolution https://k-tai.watch.impress.co.jp/img/ktw/docs/1163/500/01_o.jpg
Or just replace "_s.jpg" to "_o.jpg" :D, but it's not a safe method