the introduction text words was sheltered by the picture when device in landscape mode

[Relly]

system-image-cli -i
current build number: 100
device name: krillin
channel: ubuntu-touch/rc-proposed/bq-aquaris.en
last update: 2015-08-18 03:52:13
version version: 100
version ubuntu: 20150818
version device: 20150804-7bba081
version custom: 20150814-887-30-30-vivid

reproduce steps:
Prerequisites: Prior this case you are the first time to launch telegram app
1.rotate the device to landscape mode
2.launch telegram app
3.swipe the screen to check the backward pages.
4.until the last page (there is no button to let us to log in the app)

expected result:
for step 3 we can see the introduction words
for step 4 we can there will be a button to let us log in the app
actual result:
for step 3 the introduction picture shelter the introduction words
for step 4 the "start message" button can not display.