こういうこと?
HTML
1<figure><img src="https://placehold.jp/24/cc9999/993333/350x150.png" alt=""><figcaption>caption</figcaption></figure>
2<figure><img src="https://placehold.jp/24/cc9999/993333/150x150.png" alt=""><figcaption>caption</figcaption></figure>
3<figure><img src="https://placehold.jp/24/cc9999/993333/50x150.png" alt=""><figcaption>caption</figcaption></figure>
4<figure><img src="https://placehold.jp/24/cc9999/993333/350x50.png" alt=""><figcaption>caption</figcaption></figure>
5<figure><img src="https://placehold.jp/24/cc9999/993333/350x250.png" alt=""><figcaption>caption</figcaption></figure>
6<figure><img src="https://placehold.jp/24/cc9999/993333/350x750.png" alt=""><figcaption>caption</figcaption></figure>
CSS
1figure {
2 display: inline-block;
3 margin: .5em;
4 overflow: hidden;
5 position: relative;
6}
7figure > img {
8 display: block;
9}
10figure > figcaption {
11 background-color: rgba(10,10,10,.5);
12 color: #fff;
13 display: block;
14 position: absolute;
15 bottom: 0;
16 left: 0;
17 right: 0;
18 padding: .5em;
19 text-align: center;
20 -webkit-transform: translate(0, 100%);
21 transform: translate(0, 100%);
22 -webkit-transition: all .2s ease-in-out 0s;
23 transition: all .2s ease-in-out 0s;
24}
25figure:hover figcaption {
26 -webkit-transform: translate(0, 0);
27 transform: translate(0, 0);
28 -webkit-transition: all .5s ease-in-out 0s;
29 transition: all .5s ease-in-out 0s;
30}
31```**動くサンプル:**[https://jsfiddle.net/b2o6ecp6/](https://jsfiddle.net/b2o6ecp6/)